Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-06T14:05:58Z No. of bitstreams: 1 Gian Carlo Carvalho.pdf: 3117159 bytes, checksum: 05e217ee9f166bd343c80310a85d6838 (MD5) / Made available in DSpace on 2016-10-06T14:05:58Z (GMT). No. of bitstreams: 1 Gian Carlo Carvalho.pdf: 3117159 bytes, checksum: 05e217ee9f166bd343c80310a85d6838 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The effective use of water has been the key component for food production and for the high quality of products in the arid and semiarid regions due to the increasing lack of available water resources. The water deficit may yield several crop physiological responses from which stomatal closure and transpiration reduction stand out. The partial root drying technique has been an alternative for gain in yield an increase of water use efficiency. The objectives of the work were by means of strategies for use of PRD, to select an irrigation schedule that allow to reduce water from irrigation without significant loss of fruit yield. Yield and water use efficiency were evaluated as well root system distribution, soil water distribution and water extraction by plants. The PRD technique was applied in an experiment inside an area of Ceral farm from Organic Bioenergy Company at chapada Diamantina Lençois, county, Bahia State with the varieties of Bermuda Cherry: Junco and Rubra using 4 x 2m spacing irrigated by autocompensating drippers of 4 L h-1 flow rate. The experiment followed a random block design with two varieties, five irrigation schedules and three replications totalizing 30 experimental plots. The irrigation schedules were based upon the percent of reduction of calculated water depth, that was fixed in 50% and on the time for switching irrigation side of the plant (7, 14, and 21 days), where: (PRD 7 – reduction of 50% ETc switching plant side every 7 days, PRD 14 – reduction of 50% ETc switching plant side every 14 days, PRD 21 – reduction of 50% ETc switching plant side every 21 days, IF – reduction of 50% ETc keeping the irrigation just at one side of the plant during the whole cycle e IP – full irrigation, i.e., 100% ETc). The largest productivities were registered when irrigation has supplied 100%ETc and for PRD with reduction 50% ETc switching plant sides every 7 and 14 days. The water use efficiency was larger for irrigation schedule with PRD by switching irrigated plant side every 7 days whose value was twice the one for treatment with 100% ETc. Soil water distribution is similar for all schedules six hours after irrigation. Soil water available to plants did not reduce so drastically at the non irrigated side for PRD with change in irrigation side every 7 days compared to others treatments. This resulted in larger yields for this treatment. The root system showed larger development at shallower soil layers. The regions of larger water extraction are influenced by amount of available water and by root length density. / A utilização eficaz da água tem se tornado uma componente chave na produção de alimentos e da alta qualidade dos produtos nas regiões áridas e semiáridas, devido à crescente falta de recursos hídricos disponíveis. O déficit hídrico pode provocar diversas respostas fisiológicas nas culturas, destacando-se o fechamento dos estômatos e a redução da transpiração. Dentre as técnicas de irrigação que utilizam déficit hídrico, o secamento parcial do sistema radicular (PRD) tem se mostrado uma alternativa para ganhos em produtividade e aumento da eficiência do uso de água. Os objetivos do trabalho foram, através das estratégias de uso do PRD, selecionar um manejo de irrigação que permita reduzir o consumo de água sem perdas significativas na produção dos frutos. Para isso, avaliou-se a produtividade, eficiência do uso de água, distribuição do sistema radicular, distribuição de água no solo e extração pelas plantas. A técnica do PRD foi aplicada em um experimento em uma área de aceroleira, na fazenda Ceral, pertencente à empresa Bioenergia Orgânicos, localizada na chapada Diamantina, Município de Lençóis – BA. As variedades utilizadas foram Junco e Rubra, com espaçamento 4 x 2 m, irrigadas por gotejadores autocompensantes com vazão de 4 L h-1. O experimento seguiu delineamento em blocos casualizados, com cinco manejos de irrigação, três repetições e duas variedades, totalizando 30 parcelas experimentais. Os manejos foram baseados na percentagem de redução da lâmina calculada de irrigação, fixada em 50%, e no tempo de alteração da irrigação de cada lado da planta (7, 14 e 21 dias), sendo, PRD 7 – redução de 50% da ETc, alternando a cada 7 dias, PRD 14 – redução de 50% da ETc, alternando a cada 14 dias, PRD 21 – redução de 50% da ETc, alternando a cada 21 dias, IF – irrigação fixa em um lado da planta com redução de 50% da ETc em todo o ciclo e IP – irrigação plena, ou seja,100% da ETc em ambos os lados da planta. As maiores produtividades foram registradas para os manejos de PRD com alternância de 7 e 14 dias juntamente com o manejo de irrigação plena. A eficiência do uso de água foi maior para o manejo de irrigação PRD, com alternância de 7 dias, superior ao dobro do tratamento com 100% da ETc. O comportamento da distribuição de água no perfil do solo seis horas após a irrigação, no lado irrigado, é semelhante para todos os manejos. No lado submetido à secamento, no manejo PRD, com alternância de 7 dias, a quantidade de água disponível para as plantas não diminuiu tão drasticamente quanto nos demais manejos o que resultou na maior produtividade absoluta destas. O sistema radicular apresentou maior desenvolvimento nas camadas mais superficiais do solo. Quanto às regiões de maior extração de água no solo, estas sofrem influência em relação à quantidade de água disponível e densidade de comprimento de raízes.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-18T11:57:42Z No. of bitstreams: 1 Ligia Borges Marinho.pdf: 6523929 bytes, checksum: 33ade733585d1cbbe9567d615e5974e4 (MD5) / Made available in DSpace on 2016-10-18T11:57:42Z (GMT). No. of bitstreams: 1 Ligia Borges Marinho.pdf: 6523929 bytes, checksum: 33ade733585d1cbbe9567d615e5974e4 (MD5) Previous issue date: 2008-01-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The viticulture in the São Francisco Valley region has been growing at a significant pace in this decade, being responsible for about 90% of table grape export of the country in 2004. Irrigation practices have been adjusted in order to meet the need to culture water e to reduce irrigation water costs. The aim of this work was to evaluate the Superior seedless table grape when subjected to controlled water in the maturation stage of the grape, the water use efficiency and post-harvest performance, in the submédio region of the São Francisco River, in Casa Nova, Bahia. The statistical design was in random blocks, in a factorial scheme of 3x3 with four replicates, with timing of irrigation cut-off of irrigation depths (at 21,13, and 5 days before harvest) and three liquid blades of irrigation applied ( 100% ETc, 50% ETc and 0% ETc) and an additional treatment which represented the grower´s practice. The vines used between 335 mm and 390 mm of water in the production cycle, with a water economy of 48.5%and 94.5% for the deficit treatments in relation to the treatment that received the highest amount of water during the maturation stage of the grape. The soil water matric potential varied from -4 kPa beforematuration up to a maximum -73.6 kPa during treatment application. Water use efficiency varied between 6.42 kg.m-3 to 9.32 kg.m-3 of water , and the pre-dawn leaf water potential ranged from -0.1 MPa to -0.25 MPa and mid-day leaf water potential between -1.0 MPa and -1.8 MPa. The average grape diameter, bunch weight and yield were not significantly affected at the Duncan´s 5% level, however the number of bunches varied between 29 to 38, with weights of from 610 g to 690 g. The firmness was not influenced by the regulated deficits applied in the post-harvest conservation. The values of SS, AT and the SS/TA relationship at harvest were all equal or higher than export standards, ranging from 15.9 ºBrix to 17.2 ºBrix, 0.43 g of tartaric acid/100ml of juice to 0.467 g of tartaric acid/100ml of juice and SS/TA relationships between 35.66 and 39.72. In the post-harvest conservation period the values of SS varied from 15.81 ºBrix to 16.68 ºBrix, the TA varied from 0.42 g of tartaric acid/100ml of juice to 0.46 g of tartaric acid/100ml of juice, whereas the SS/TA varied from 37.76 to 36.35 at 28 days from cold chamber storage. / A viticultura na região do Vale do São Francisco vem apresentando um crescimento bastante significativo nesta década, tendo sido, responsável por cerca de 90% das exportações de uva de mesa do país, em 2004. As práticas de irrigação têm sido ajustadas com o fim de atender a demanda de água da cultura e reduzir o consumo de água na irrigação. O objetivo do trabalho foi avaliar a videira cv. Superior Seedless quando submetida a déficits hídricos controlados de água na fase da maturação da uva, eficiência de uso de água e conservação pós-colheita, na Região do Submédio São Francisco, Casa Nova-BA. Utilizou-se o delineamento estatístico em bloco ao acaso, em esquema fatorial 3x3 com quatro repetições, sendo três épocas de corte na aplicação das lâminas (aos 21, 13 e 5 dias antes da colheita) e três lâminas líquidas de irrigação (100% , 50% e 0%) e um tratamento adicional, o qual correspondeu ao manejo adotado pelo produtor. O consumo hídrico da videira variou entre 335 mm e 390 mm no ciclo de produção, que resultou em uma economia de água que variou de 48,5% a 94,5% para os tratamentos deficitários em relação ao tratamento com maior suprimento de água, durante a fase de maturação da uva. Os potenciais matriciais da água no solo variaram em média de -4 kPaantes da maturação até um máximo de -73,6 kPa, durante a aplicação dos tratamentos. A eficiência do uso de água variou de 6,42 kg.m-3 a 9,32 kg.m-3 de água. O potencial hídrico foliar antes do alvorecer variou entre -0,1 MPa e -0,25 MPa e ao meio dia entre -1,0 MPa a -1,80 MPa. A média de diâmetro de bagas de uva e peso de cacho não foram afetados significativamente, pelo teste Duncan a 5%, no entanto o número de cachos variou de 29 a 38, com peso de 610 g a 690 g. A firmeza não sofreu influência do déficit hídrico regulado, após armazenamento em câmara fria. Os valores dos atributos: sólidos solúveis (SS), acidez total (AT) e a relação de SS/AT, por ocasião da colheita, formam iguais ou superiores aos padrões exigidos para exportação, variando de 15,9 ºBrix a 17,20 ºBrix, 0,43 g de ácido tartárico/100 ml de suco a 0,467 g de ácido tartárico/100 ml de suco e de 35,66 a 39,72, respectivamente. Na conservação pós-colheita obteve-se valores de SS variando de 15,81 ºBrix a 16,68 ºBrix; AT passando de 0,42 g de ácido tartárico/100 ml de suco para 0,46 g de ácido tartárico/100 ml de suco e a relação SS/AT decrescendo de 37,76 para 36,35, após 28 dias armazenamento, em câmara fria.

Made available in DSpace on 2016-12-23T14:37:44Z (GMT). No. of bitstreams: 1 Joao_Vitor_Toledo.pdf: 607615 bytes, checksum: dab692118bf86f9eb81d6ef843ae5306 (MD5) Previous issue date: 2012-01-24 / O eucalipto é a espécie florestal de rápido crescimento mais utilizada no Brasil, sendo o seu cultivo um dos mais avançados, produtivos e competitivos do mundo. O estresse induz mudanças e respostas em todos os níveis funcionais do organismo vegetal. O déficit hídrico, portanto, causa alterações no comportamento e desenvolvimento vegetal, e dependendo do genótipo, este pode ser mais ou menos tolerante a condições adversas do clima. Objetivou-se com este trabalho avaliar a influência de diferentes regimes hídricos em relação à água disponível no solo, sobre o crescimento e o desenvolvimento, durante 60 dias da fase de estabelecimento, de três clones de eucalipto, do híbrido Eucalyptus urophylla x Eucalyptus grandis. Este estudo foi desenvolvido em casa de vegetação instalada na área experimental do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo, localizada no município de Alegre- ES. O experimento foi montado no esquema Fatorial 3x3 em delineamento experimental em blocos casualizados. Os tratamentos constituíram-se da interação de três níveis de água disponível no solo (50%, 30% e 10%), com o fator clones (Clone 1, Clone 2 e Clone 3), com quatro repetições. As mudas foram cultivadas em vasos com volume de 30 dm³. O controle dos níveis de depleção foi realizado através do monitoramento da massa de cada vaso, com o auxílio de uma balança, sendo a umidade elevada até a capacidade de campo até obter a umidade referente ao tratamento. Foram avaliados os valores de altura, diâmetro, número de folhas, área foliar, matéria seca total, matéria seca de folhas, matéria seca de raiz, matéria seca de haste e ramos, volume de raiz, lâmina total consumida e eficiência do uso da água. Os dados foram submetidos à análise de variância, e quando significativas, as médias foram comparadas pelo teste de Tukey ao nível de 5% de probabilidade. As avaliações executadas indicam que os níveis de disponibilidade de água abaixo de 50% da água disponível prejudicam o crescimento de todos os clones. A redução média da matéria seca total dos três clones estudados é de 21% e 40% para os níveis de 30% e 10%, respectivamente, em relação à produção de biomassa das plantas submetidas a 50% da água disponível. O Clone 2 apresenta médias estatisticamente superiores aos demais nos parâmetros matéria seca, número de folhas e eficiência do uso da água, se mostrando, portanto, superior sob condição de restrição hídrica. Portanto, o Clone 2 é mais indicado para implantação em regiões tanto com maior como menor disponibilidade hídrica / Eucalyptus is a fast growing tree species most used in Brazil, and its cultivation is of the most more advanced, productive and competitive in the world. Stress induces changes and responses in all functional levels the plant organism. The water deficit therefore causes changes in behavior and plant development, and depending on the genotype, it may be more or less tolerant to adverse weather conditions. The objective of this work was evaluate the influence of different regimes water through the water availability in the soil on the growth and development during 60 days of phase establishment of three eucalyptus clones, the hybrid Eucalyptus grandis x Eucalyptus urophylla. This study was conducted in a greenhouse attached to the experimental area of the Centro de Ciências Agrárias of Universidade Federal of Espírito Santo, located in municipality of Alegre-ES. The experiment was arranged with a 3x3 factorial arrangement in experimental randomized blocks design. The treatments consisted of interaction of three levels of available soil water (50%, 30% and 10%), with the clones factor (Clone 1, Clone 2 and Clone 3) with four replications. The seedlings were grown in vessels with a volume of 30 dm³. The control of the levels of depletion was performed by monitoring the mass of each vessel with the aid of a scale, being the humidity high up to capacity field until it obtains the moisture related to the treatment. It was evaluated values of height, diameter, leaf number, area leaf dry weight, dry leaves, root dry matter, dry stem and branches, root volume, depth and efficiency of the total consumed use of water. Data were analyzed by variance, and when significant, means were compared by Tukey test at level 5% probability. The evaluations performed indicate that the water availability levels below 50% of water available affect the growth of all clones. The average reduction of total dry matter of the three clones studied is 21% and 40% at levels of 30% and 10% respectively, for the production of biomass from plants subjected to 50% of available water. The Clone 2 presents averages statistically superior to the other in dry parameters, number of leaves and efficiency of water use, proving therefore more subject to water restriction. Therefore, the Clone 2 is more suitable for deployment in both regions more and less water availability

Les plantations d’hévéa (Hevea brasiliensis) s’étendent vers des zones non traditionnelles de production en Thaïlande où des conditions plus sèches ont pu conduire à une diminution de la croissance des arbres et de la production de latex. Des paramètres physiologiques utiles pour sélectionner des génotypes adaptés sont nécessaires, comme l’efficience d’utilisation de l’eau (WUE). La discrimination isotopique du carbone est largement utilisée comme proxy pour WUE et peut être aisément utilisée dans des programmes de sélection pour la tolérance à la sécheresse. δ13C des feuilles et les échanges gazeux foliaires ont été mesurés sur de jeunes plants de dix clones d’hévéa cultivés en pot dans une pépinière. La gamme de δ13C des feuilles entre ces dix clones était restreinte et la corrélation entre δ13C et WUEi était significative que sous fort déficit de pression de vapeur saturante, ce qui signifie que la prédiction de WUE par δ13C serait peu précise. Il y avait une large gamme de δ13C entre les génotypes dans une collection de 49 génotypes sauvages d’hévéa cultivés dans le nord-est de la Thaïlande en saison sèche et en saison des pluies. δ13C était relativement stable avec une bonne corrélation entre les saisons. Cette étude montre que la variabilité génétique de δ13C est prometteuse pour des futurs programmes de sélections si une bonne corrélation entre δ13C et WUE peut être établie. L’absence de corrélation entre de δ13C du latex (δ13C-L) et des composés solubles extraits des feuilles (δ13C-S) prélevées sur des arbres saignés et non saignés âgés de 20 ans suggère que photosynthétats récemment produits se mélangent à un stock important d’hydrate de carbone impliqués dans la régénération du latex après la saignée. Donc, δ13C du latex n’est pas un indicateur pertinent de WUE / The rubber (Hevea brasiliensis) plantations extend to non-traditional area in Thailand where dryer conditions has been reported to impair the growth of rubber trees and latex production. Physiological parameters helpful for breeding adapted genotypes are required, such as water use efficiency (WUE). Carbon isotope discrimination is widely used as a proxy for WUE that can easily be used for selection and breeding programs for drought tolerance. Leaf δ13C and leaf gas exchange were measured on young saplings of 10 rubber clones growing in pot in a common garden. The range of leaf δ13C among 10 clones was narrow and the correlation between δ13C and WUEi was significant under high vapour pressure deficit only, which means the prediction of WUE by δ13C would have low precision. There were large δ13C variations among the genotypes at all seasons in a collection of 49 wild genotypes of rubber in Northeastern Thailand. δ13C was rather stable with a good correlation between rainy and dry season. The genetic variability of δ13C is promising for breeding if a good correlation between δ13C of leaf and WUE can be established. The lack of correlation between δ13C of latex (δ13C-L) and of leaf soluble compounds (δ13C-S) collected from tapped and untapped 20 year-old rubber trees suggests that recent photosynthates are mixed in the large pool of stored carbohydrates that are involved in latex regeneration after tapping. Thus δ13C of latex is not a relevant indicator of WUE of rubber trees

L’efficience d’utilisation de l’eau (WUE), rapport entre la biomasse produite et l’eau consommée, est un trait essentiel à étudier en agronomie pour améliorer la production des cultures soumises à la sécheresse. Cependant, mesurer l’eau consommée par un couvert végétal est difficile à réaliser. L’objectif général de ce travail de thèse est de répondre à trois principales questions : (i) peut-on déterminer WUE en utilisant la discrimination isotopique du carbone (CID) facile à mesurer? (ii) comment l’analyse de la variabilité de WUE et CID peut contribuer à sélectionner des génotypes de tournesol soumis à la sécheresse? (iii) et les variations de WUE peuvent-elles être révélées par les variations de relations hydriques? Quatre expériences ont été conduites en serre pendant deux années : (i) avec deux scenario de sécheresse, l’une progressive, l’autre stable, et (ii) avec cinq niveaux de contenu en eau du sol stables. Les principaux traits mesurés sont WUE, CID et d’autres traits représentant les relations hydriques tels que le contrôle de la transpiration (FTSWt), la capacité d’extraction de l’eau (TTSW) et la tolérance à la déshydratation (OA). Une forte corrélation négative a été mise en évidence entre WUE et CID. Une large variabilité a également été observée pour FTSWt, TTSW et OA. Ces résultats permettent de connaitre le contrôle génétique de WUE et CID, ainsi que des traits associés, lesquels n’ont jamais été relatés dans la littérature. De plus, l’analyse QTL pour FTSWt n’a pas non plus été réalisée, chez aucune plante. Des QTL pour WUE et CID ont été identifiés pour différents scenario de sécheresse. Les QTL pour CID sont considérés comme ‘constitutifs’, parce qu’ils sont détectés dans les différents scenarios. Les QTL pour CID co-localisent avec ceux pour WUE, pour la biomasse et pour la transpiration cumulée. Des co-localisations de QTL ont également été observées entre FTSWt et TTSW, entre TTSW et WUE-CID-Biomasse, et entre FTSWt-TTSW et Biomasse. Cette étude met en évidence que WUE est physiologiquement et génétiquement associée à CID. De plus, CID représente un excellent substitue à la mesure de WUE et permet d’améliorer l’efficience d’utilisation de l’eau par sélection assistée par marqueurs. / Water use efficiency (WUE), measured as the ratio of plant biomass to water consumption, is an essential agronomical trait for enhancing crop production under drought. Measuring water consumption is logistically difficult, especially in field conditions. The general objective of the present Thesis is to respond to three main questions: (i) can WUE be determined by using carbon isotope discrimination (CID), easy to measure?, (ii) how WUE and CID variation analysis can contribute to the genotypic selection of sunflower subjected to drought?, and (iii) can WUE variation be revealed by the variation of plant-water relation traits. Four experiments were carried out in greenhouse across two different years: (i) on two drought scenarios, progressive soil drying and stable water-stress, and (ii) on five levels of soil water content. The main traits that have been measured include WUE, CID, as well as plant-water relation traits, i.e. control of transpiration (FTSWt), water extraction capacity (TTSW), and dehydration tolerance (OA). A highly significant negative correlation was observed between WUE and CID, and a wide phenotypic variability was observed for both WUE and CID. A wide variability was also observed for FTSWt, TTSW and OA. The results provide new insight into the genetic control of WUE and CID related-traits, which, unlike to other crops, genetic control of WUE, CID, and TTSW in sunflower have never been reported in the literature. Further, quantitative trait loci (QTL) mapping for FTSWt was never reported in any plant species. The QTL for WUE and CID were identified across different drought scenarios. The QTL for CID is considered as a ‘‘constitutive’’ QTL, because it is consistently detected across different drought scenarios. The QTL for CID co-localized with the QTL for WUE, biomass and cumulative water transpired. Co-localization was also observed between the QTL for FTSWt and TTSW, between the QTL for TTSW and WUE-CID-biomass, as well as between the QTL for FTSWt-TTSW and biomass. This study highlights that WUE is physiologically and genetically associated with CID. CID is an excellent surrogate for WUE measurement, and can be used to improve WUE by using marker-assisted selection (MAS) to achieve the ultimate goal of plant breeding at genomic level.

Quercus robur et Quercus petraea sont deux espèces de chêne sympatriques occupant des niches écologiques distinctes et présentant des différences de sensibilités à la sécheresse. La littérature disponible suggère qu’il existe des différences inter-spécifiques stables de l’efficience d’utilisation entre ces deux espèces, Q.petraea présentant des valeurs supérieures à Q.robur. L’efficience d’utilisation de l’eau peut être étudiées à différentes échelles d’intégration spatiales et temporelle. Sur la base de mesures instantanées d’échanges gazeux foliaires, l’efficience d’utilisation de l’eau intrinsèque (Wi) peut être déterminée. D’autre part, l’efficience d’utilisation de l’eau peut être caractérisée par des mesures de composition isotopique du carbone (δ13C) au sein des tissus végétaux ou par l’estimation de l’efficience de transpiration plante entière (TE), permettant ainsi une estimation de l’efficience intégrée dans le temps. La caractérisation de l’efficience à travers ces différents estimateurs a permis de mettre en évidence chez des semis croissant en conditions contrôlées une efficience de transpiration supérieure chez Q.robur bien qu’aucune différence ne soit détectable entre les deux espèces sur la base des mesures instantanées (Wi). Ces variations de TE étaient essentiellement liées aux variations de la production de biomasse par les plants tandis que les variations de Wi qui ont été observées étaient principalement associées à la conductance stomatique. Les variations intra et inter espèces de la dynamique de réponse stomatique au changement abrupte d’un facteur environnemental (lumière, CO2, VPD) n’ont pu être clairement reliées aux variations des différents estimateurs de l’efficience ou leur composantes respectives. Par ailleurs, les conditions de stress hydriques impactaient la dynamique de réponse stomatique chez les deux espèces de chênes. Cet impact se traduit par des réponses stomatiques plus rapides. Les principales différences observées entre les espèces étaient liées à la production de biomasse. Les deux espèces affichaient en effet des stratégies d’allocation du carbone divergentes notamment au niveau du compartiment racinaire. Ainsi Q.petraea produisait un système racinaire plus fin et ramifié que Q.robur. Par ailleurs, cet état de fait était plus marqué sous conditions de stress, conditions à laquelle Q.robur est plus sensible que Q.petraea en terme de production de biomasse. La complexité des relations entre efficience d’utilisation de l’eau et l’ensemble des traits physiologiques et anatomiques étudiés ainsi que leurs possibles implications dans la tolérance à la sécheresse des deux espèces de chênes sont discutées dans cette synthèse. / Quercus robur L. and Quercus petraea (Matt.) Liebl. are two sympatric oak species occupying distinctive ecological niches as well as presenting disparate drought tolerances. Available litterature reports the existence of stable inter-specific differences of water use efficiency (WUE) between the two species, Q. petraea displaying higher values than Q. robur. Water use efficiency can be studied at several integration scales both spatially and temporally. Based on instantaneous foliar gaz exchange, the intrinsic water use efficiency can be determined (Wi). On the other hand, water use can be characterised by measurements of the carbon isotopic composition of plant tissues (13C) or by estimation of the whole plant transpiration efficiency (TE), thus allowing a time-integrated estimate of water use. The characterisation of WUE through these different estimators allowed us to put in evidence in oak seedlings grown under controlled conditions a higher transpiration efficiency in Q. robur even though no differences were observed between the two species regarding instantaneous measurements (Wi). TE variations were mainly linked to the variations of the biomass production by the plants while Wi variations were essentially associated to the stomatal conductance. Both intra and inter specific variations of the dynamics of stomatal response to step changes of environmental factors (light, CO2, VPD) could not be clearly linked to the variations of the different WUE estimates nor their respective components. Nevertheless, drought conditions impacted the stomatal dynamics in both species towards faster stomatal responses, especially for stomatal closing. Furthermore, the main observed differences between species were linked to biomass production. Both species displayed different carbon allocation strategies, especially regarding the root compartment. Thus, Q. petraea produced a significantly more ramified and thinner root system than Q. robur. Such behaviour was accentuated under drought stress, under which Q. robur was more sensitive than Q. petraea in term of biomass production. The complexity of the relationships between water use efficiency and all of these morphological and physiological traits as well as the possible drought tolerance implications in both oak species are discussed in this PhD thesis.

No description available.

[ES] La escasez de agua se está convirtiendo en un problema en zonas áridas y semiáridas del mundo, donde se localiza parte de la producción de los principales cultivos hortícolas, como en el área mediterránea. La sequía es uno de los principales factores limitantes en la agricultura y está afectando gravemente a la producción de cultivos hortícolas. La mejora de la productividad del agua en la agricultura puede lograrse mediante la utilización de determinadas estrategias. El riego deficitario consiste en el aporte de agua por debajo de las necesidades de riego (NR) de los cultivos, de manera que se produce una reducción de la evapotranspiración. Puede realizarse de manera continua o sostenida (RDS) o controlada (RDC). Con el riego deficitario se puede mejorar la eficiencia del uso del agua de riego, manteniendo el rendimiento, e incluso en ocasiones, podría mejorarse la calidad de la cosecha. En este estudio, realizado en el Centro Experimental Cajamar de Paiporta (Valencia) se evalúa el efecto del riego deficitario en cuatro de los principales cultivos hortícolas cultivados al aire libre, en el área mediterránea: coliflor, cebolla, pimiento y sandía. En la evaluación se ha analizado: crecimiento y estado hídrico de las plantas, rendimiento, eficiencia del uso del agua de riego, calidad de la producción y rentabilidad de los cultivos. En la primera campaña se ensayó el RDS, lo que permitió establecer las diferentes etapas de crecimiento de cada cultivo, que se utilizaron en las siguientes campañas en el RDC. En los cuatro cultivos, las plantas control (100% NR) han mostrado un adecuado estado hídrico, tanto en el contenido relativo de agua como en el índice de estabilidad de la membrana, mientras que las sometidas a un RDS severo, han mostrado los menores valores de ambos índices. El efecto negativo del riego deficitario sobre el rendimiento ha resultado menos importante en los cultivos de otoño-invierno que en los cultivos de primavera-verano, especialmente en la coliflor. El RDS del 50% NR ha reducido drásticamente el rendimiento comercial y, consecuentemente, los ingresos brutos, aunque haya supuesto una mejora en la eficiencia del uso del agua de riego para los cultivos de otoño-invierno. Del análisis individual de los cultivos se deduce que el rendimiento en pellas de coliflor obtenidas con RDS al 75% NR o RDC al 50% NR durante la fase juvenil, se ha mantenido en niveles similares al control, mejorando la eficiencia del uso del agua de riego. En cebolla, en caso de restricción hídrica severa, sería aconsejable aplicar RDS con el 75% NR o RDC al 50% NR durante la maduración del bulbo, ya que estas estrategias han disminuido ligeramente el rendimiento, mejorando la eficiencia del uso del agua de riego. En condiciones menos restrictivas, RDC al 75% NR durante la maduración del bulbo ha dado lugar a un rendimiento satisfactorio, con un aumento de la eficiencia del uso del agua de riego. En pimiento dulce italiano, la aplicación de RDC al 75% NR durante la recolección ha dado lugar a una reducción considerable del rendimiento, y por tanto, de los ingresos brutos, aunque con importantes ahorros de agua y con un incremento en el contenido de sólidos solubles y de compuestos fenólicos de los frutos. Acortando el ciclo de cultivo hasta principios de septiembre, cuando ya se ha cosechado la mayor parte del rendimiento comercial, se conseguiría un importante ahorro de agua y permitiría utilizar la parcela en otros cultivos. El RDS al 75% y al 50% NR, o RDC al 50% NR durante la cosecha han dado lugar a una alta incidencia de frutos afectados por blossom-end rot. En sandía puede recomendarse la aplicación de RDC, tanto al 75% como al 50% NR durante la maduración del fruto, ya que ha conducido a rendimientos comerciales aceptables. De manera general se puede afirmar que la aplicación de RDS y de RDC en los cuatro cultivos, no ha afectado de manera importante a la calidad de la producción, / [CAT] Resum L'escassesa d'aigua s'està convertint en un problema en zones àrides i semiàrides del món, on es localitza part de la producció dels principals cultius hortícoles, com és el cas de l'àrea mediterrània. La sequera és un dels principals factors limitants en l'agricultura i està afectant greument a la producció de cultius hortícoles. La millora de la productivitat de l'aigua en l'agricultura en general, i en l'horticultura en particular, es pot aconseguir mitjançant la utilització de determinades estratègies. El reg deficitari consisteix en l'aportació d'aigua per sota de les necessitats de reg (NR) dels cultius, de manera que es produeix una reducció de l'evapotranspiració. Es pot fer de manera contínua o sostinguda (RDS) o controlada (RDC). Amb el reg deficitari es pot millorar l'eficiència de l'ús de l'aigua de reg, mantenint el rendiment, i fins i tot de vegades, podria conduir a una millora de la qualitat de la collita. En aquest estudi, realitzat al Centre Experimental Cajamar de Paiporta (València, Espanya) s'avalua l'efecte del reg deficitari en quatre dels principals cultius hortícoles conreats a l'aire lliure, a l'àrea mediterrània: dos de cultiu de tardor-hivern (coliflor i ceba) i dues de cultiu primaveral-estival (pimentó i meló d'Alger). En l'avaluació s'han analitzat els següents paràmetres: creixement i estat hídric de les plantes, rendiment, eficiència de l'ús de l'aigua de reg, qualitat de la producció i rendibilitat dels cultius. A la primera campanya es va assajar el RDS, el que va permetre establir les diferents etapes de creixement de cada cultiu, que es van utilitzar en les següents campanyes en el RDC. En els quatre cultius, les plantes control (100% NR) han mostrat un adequat estat hídric, tant en el contingut relatiu d'aigua com en l'índex d'estabilitat de la membrana, mentre que les sotmeses a un RDS sever, han mostrat els menors valors d'ambdós índexs. L'efecte negatiu del reg deficitari sobre el rendiment ha resultat menys important en els cultius de tardor-hivern que en els cultius de primavera-estiu, especialment en la coliflor. El RDS del 50% NR ha reduït dràsticament el rendiment comercial i, conseqüentment, els ingressos bruts, encara que hagi suposat una millora en l'eficiència de l'ús de l'aigua de reg per als cultius de tardor-hivern. De l'anàlisi individual dels cultius es dedueix que el rendiment de coliflors obtingudes amb RDS al 75% NR o RDC al 50% NR durant la fase juvenil, s'ha mantingut en nivells similars al control, millorant l'eficiència de l'ús de l'aigua de reg. En ceba, en cas de restricció hídrica severa, seria aconsellable aplicar RDS amb el 75% NR o RDC al 50% NR durant la maduració del bulb, ja que aquestes estratègies han disminuït lleugerament el rendiment, millorant l'eficiència de l'ús de l'aigua de reg . En condicions menys restrictives, RDC al 75% NR durant la maduració del bulb ha donat lloc a un rendiment satisfactori, amb un augment de l'eficiència de l'ús de l'aigua de reg. En pimentó dolç italià, l'aplicació de RDC al 75% NR durant la recol·lecció ha donat lloc a una reducció considerable del rendiment, i per tant, dels ingressos bruts, encara que amb importants estalvis d'aigua i amb un increment en el contingut de sòlids solubles i de compostos fenòlics dels fruits. Retallant el cicle de cultiu fins a principis de setembre, quan ja s'ha collit la major part del rendiment comercial, s'aconseguiria un important estalvi d'aigua i permetria utilitzar la parcel·la en altres cultius. El RDS al 75% i al 50% NR, o RDC al 50% NR durant la collita han donat lloc a una alta incidència de fruits afectats per blossom-end rot. En meló d'Alger es pot recomanar l'aplicació de RDC, tant al 75% com al 50% NR durant la maduració del fruit, ja que ha conduït a rendiments comercials acceptables. De manera general es pot afirmar que l'aplicació de RDS i de RDC en els quatre cultius, no ha afectat de maner / [EN] Water scarcity is becoming a critical problem in arid and semi-arid areas of the world, where part of the production of the main horticultural crops is located, as is the case of the Mediterranean area. Drought is one of the main limiting factors in agriculture and it is seriously affecting the production of horticultural crops. The improvement of water productivity in agriculture in general, and in horticulture in particular, can be achieved through the use of certain strategies. Deficit irrigation consists of the supply of water below the irrigation water requirements (IWR), so that there is a reduction in evapotranspiration. It can be done continuously (CDI) or regulated (RDI). With deficit irrigation, the irrigation water use efficiency can be improved, maintaining yield, and it could even lead to an improvement in the quality of the harvest. This study, carried out at the Cajamar in Paiporta Experimental Center (Valencia, Spain), analyzes the effect of deficit irrigation on four of the main cultivated horticultural crops, open field cultivated in the Mediterranean area: two of autumnal-winter crops (cauliflower and onion) and two spring-summer crops (pepper and watermelon). In the evaluation, the following parameters have been analyzed: plant growth and water status, yield, irrigation water use efficiency, quality of production and crop profitability. In the first season the CDI was tested, which allowed to establish the different growth stages for each crop, which were used in the following season for the RDI. In the four crops, the control plants (100% IWR) have shown an adequate water status, in terms of both relative water content and membrane stability index, while those subjected to a severe CDI, have shown the lowest values of both indexes. The negative effect of deficit irrigation on yield has been less important in autumn-winter crops than in spring-summer crops, especially in cauliflower. The CDI at 50% IWR has drastically reduced the marketable yield and, consequently, the gross revenue, although it has supposed an improvement in the irrigation water use efficiency for the autumn-winter crops. From the individual analysis of the crops, it can be stated that cauliflower yield obtained with CDI at 75% IWR or RDI at 50% IWR during the juvenile phase, has remained at levels similar to the control, improving the irrigation water use efficiency. In relation to onion, in case of severe water restriction, it would be advisable to apply CDI with 75% IWR or RDI at 50% IWR during bulb ripening, since these strategies have slightly decreased yield, improving the irrigation water use efficiency. In less restrictive conditions, RDI at 75% IWR during the bulb maturation has led to a satisfactory yield, with an increase in the irrigation water use efficiency. In Italian sweet pepper, the application of RDI to 75% IWR during the harvesting has resulted in a considerable reduction of the yield, and therefore, of the gross income, although with important water savings and increasing the fruit soluble solids and phenolic compounds content. By shortening the cultivation cycle until the beginning of September, when most of the marketable yield has already been harvested, significant water savings would be achieved, and the land could be used in other crops. CDI at 75% IWR and 50% IWR, or RDI at 50% IWR at harvesting have resulted in a high incidence of fruit affected by blossom-end rot. In watermelon the RDI application can be recommended, both 75% and 50% IWR, during the fruit ripening, since it has led to acceptable marketable yields. In general terms, it can be affirmed that the application of CDI and RDI in the four crops has not significantly affected the product quality, in terms of the analyzed parameters. / My grateful thanks to the Cultural Affairs and Mission Sector, Egyptian Ministry of Higher Education for supporting me with a scholarship. / Abdelkhalik, AGA. (2019). Effect of continued and regulated deficit irrigation on the productivity of four vegetable crops in open-field conditions in the Mediterranean area [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/129868 / TESIS

The United States (US) has experienced a surge in water shortages and droughts in recent times. Water shortages can result from population growth, climate change, inadequate water management policies, and the improper use of available technologies. The existing data and research on water use associated with water management policy structures are limited. Many states in the US follow strict regulations on water discharge into streams to enforce water quality standards; however, water withdrawal restrictions from streams are limited and inadequate in terms of water management at times of low flow. In states such as Virginia (VA), the Virginia Department of Environmental Quality (VDEQ) requires a Virginia Water Protection (VWP) permit for all water withdrawals from VA's surface waters. However, under certain provisions of VWP regulations, users are exempted from having a permit. Such permit exemptions exist in many states and present a severe challenge to water supply management. Chapter 2 compares the impact of permit exemptions on surface water availability and drought flows and compares these impacts to the relatively well-studied risks presented by dry climate change and demand growth in Virginia (VA). It was observed that in some regions, the impacts under the exempt user scenario were higher than those under the dry climate change scenario. In addition, water supply managers and government agencies use user-reported water withdrawal data to develop water management programs. Irrigated agriculture is the largest source of water consumption in the US. However, water-reporting regulations exempt users from withdrawing water for irrigation under a certain threshold. Moreover, as water is not metered, users often do not report their irrigation water use, resulting in considerable uncertainty about the impacts of irrigation withdrawals, which could potentially impact other water users, lead to water shortages or conflicts, and negatively impact stream ecology. Chapter 3 focuses on developing a novel methodology for quantifying unreported irrigation water withdrawals using publicly available USDA-Census and USDA-IWMS datasets. This method was used to evaluate the unreported water withdrawals in the VA. Finally, water use practices at the field level intersect with other environmental issues at a larger scale. For example, irrigation practices can influence nutrient uptake and transport at the field level. Insufficient water for irrigation, especially during critical growth stages, results in yield and economic losses and reduces agricultural productivity. However, excessive irrigation can lead to wasted water and energy as well as runoff and leaching of nutrients and agricultural chemicals. Therefore, the adoption of technological advancements at the field scale can reduce the amount of water needed to fulfill the needs while mitigating any nutrient impacts on the soil due to the excessive use of water. This is highly important when fertilizer prices are always high. Chapter 4 focuses on quantifying the impact of the use of short-term weather forecast data in irrigation scheduling on nutrient and water use efficiency in humid climates: experimental results for corn and cotton. It was found that irrigation scheduling using short-term weather forecast data is helpful for improving the nutrient and water use efficiency of corn. For cotton, nutrient and water use efficiency are highly influenced by irrigation and precipitation with respect to the growth stage. / Doctor of Philosophy / Water shortages in the US have increased in recent times owing to climate change. Water demand is expected to increase in the future due to population growth and economic development in certain regions. Water supply planning is significantly influenced by water policy regulations. Water withdrawal regulations mandate a water withdrawal permit for making withdrawals in many states across the US. However, due to provisions in the same water regulations, certain users are exempt from taking a water withdrawal permit. One example of such users is grandfathered users who had a water withdrawal permit before July 1, 1989, in Virginia. Such exemptions are a severe challenge to the management of water supply, as exempt withdrawal amounts are generally high. We studied the impacts of these exempt users on VA's water resources of VA and compared them with the impacts of dry climate change and 2040 demand growth in Chapter 2. The results indicate that the impact of exempt users is higher than that of climate change in some regions across VA. Additionally, water-reporting regulations require users to report irrigation water withdrawals. However, users below the reporting threshold were excluded from reporting. Some users might underreport or do not comply with the water withdrawal regulations. These user-reported data are often used in developing water management plans, which may become ineffective owing to incomplete water use data. Chapter 3 focuses on the development of a data-based approach for quantifying unreported irrigation water withdrawals. This method would be transferable to any other state across the US. We compared the estimated irrigation withdrawals with reported irrigation withdrawals across the VA and generated unreported withdrawals at the county level in the VA. Finally, at the field level, irrigation can highly influence the nutrient uptake of plants. Excess irrigation may result in the removal of nutrients below the roots of the plant or may be removed by surface runoff, making it unavailable for plant uptake. Along with the economic impacts of unused fertilizer and loss in yield, unused nutrients may impact the environment and water bodies. Chapter 4 focuses on the impact of short-term weather forecast data on the irrigation scheduling of corn and cotton in humid climates. We found that weather-informed irrigation is helpful in increasing the nutrient and water use efficiency of corn. For cotton, the results were highly affected by precipitation and irrigation with respect to the growth stage of cotton.

Thesis (MScAgric)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: Biochar has been labelled to be a key factor in the global carbon mitigation act and has been described as the modern day equivalent (terra nova) to the terra preta dark earth soils of the Brazilian Amazon. Globally biochar has been evaluated as a means to improve soil fertility and to mitigate greenhouse gases (GHGs). Little research has however been published on the effects of biochar incorporation on soil physical properties. The objective of this study was to evaluate the effect of pine sawmill waste derived biochar (locally-produced via slow pyrolysis – 450°C) on selected soil physical properties, soil-water dynamics and crop production and- performance, when amended to a Kroonstad (Kd 1000 – Morgendal) soil form. This soil form is commonly found in the Western Cape area (South Africa) and can be classified as having low agricultural suitability for perennial- and annual crop species. Two pot trials were carried out in an atmospheric controlled greenhouse, where winter wheat and green beans respectively were planted, with five different application levels of biochar (0t/ha, 1t/ha, 10t/ha, 50t/ha and 200t/ha). Soil physical properties namely, water-stable aggregates, bulk density and water-retention capacity along with physiochemical characterisation of the sandy soil and biochar was determined. The water-use was monitored throughout the trials (evapotranspiration, volumetric water content and biomass water use efficiency, BWUE). The above- and below ground (specific leaf traits for the green bean and the root structural development for the winter wheat) biomass was collected and analysed at harvest. There was significantly higher volumetric water content measured for the 50t/ha and 200t/ha biochar treatments. This effect can be ascribed due to a change in the soil’s tortuosity and porosity where more meso- and micro-pores were present as the biochar rate increased. The same results were evident when a water-retention curve was established in vitro by means of the sandbox method. The bulk densities were only significantly lower for the 200t/ha biochar treatments. The wheat root systems differed greatly among the fertilised biochar treatments: the 50t/ha and 200t/ha treatments had a more complex fibrous root system (more extensive branching and thinner roots) than 0t/ha, 1t/ha and 10t/ha application levels. This is attributed to the increased water-holding capacity along with a reduction of N- and P availability with increasing addition of biochar. Several leaf traits were measured for the green bean crops; however the leaf nitrogen- and carbon content, chlorophyll content index (CCI) and carbon isotope fractionation yielded the most interesting findings. Concerning the fertilised biochar treatments, there was established that the 10t/ha treatments had the highest leaf nitrogen- and carbon content. The leaf chlorophyll content did not differ significantly between the fertilised biochar treatments; however a very interesting observation was evident regarding the measured leaf CCI for the unfertilised treatments. A decreasing trend and lower leaf CCI was measured as the biochar application levels increased. This effect was ascribed to be due to a decrease in N uptake by the plants as the biochar application increased, the C/N ratio also increased, and this leading to N immobilisation. The lowest leaf carbon isotope fractionation was measured for the 10t/ha fertilised treatments and is inversely correlated with BWUE and therefore endorses the conclusion that the 10t/ha biochar application had a positive effect on the long term water use efficiency for the green bean plants. Biochar promoted aggregation in the sand-rhizosphere interface for winter wheat, increased water-holding capacity and enhanced crop performance for green beans. The findings reported here provide new information on the effect of biochar on the structural development of sandy soil, combined with biochar- and root growth effects for winter wheat; along with detailed interpretations of specific leaf traits associated with crop production for commercial green beans. The addition of biochar at low application levels (approximately 1-10t/ha to 15 cm depth) increased the biomass yield and water use efficiency of the crop species. Besides long term carbon storage, biochar can have immediate positive effects on the physical properties of sand and plant growth. / AFRIKAANSE OPSOMMING: Biokoolstof word beskou as ‘n sleutel komponent rakende die wet op globale koolstofvermindering en is al beskryf as die moderne ekwivalent (terra nova) van die terra preta donker-aardgronde wat aangetref word in die Brasiliaanse Amasone. Wêreldwyd word biokoolstof tans geëvalueer met die doel om grondvrugbaarheid te verbeter asook kweekhuisgasse (KHG) se nadelige gevolge te verlig. Min navorsing was tot dus ver gedoen rakende die uitwerking met toediening van biokoolstof op grondfisiese-eienskappe. Die doel van hierdie studie was om die effek van biokoolstof, wat afkomstig is van denne-saagmeul-afval (plaaslik geproduseer is en d.m.v. stadige perolise - 450°C) te evalueer aangaande die volgende faktore: geselekteerde grondfisiese-eienskappe, grond-waterdinamika interaksie en die uitwerking op gewasproduksie; met toediening aan 'n Kroonstad (Kd 1000 - Morgendal) grondvorm. Hierdie grondvorm word as algemeen in die Wes-Kaap (Suid-Afrika) bestempel en kan geklassifiseer word as ‘n lae-geskiktheid landbougrond vir meerjarige- en eenjarige gewasse. Twee potproewe is uitgevoer onder beheerde atmosfeer in ‘n kweekhuis, waar winter koring en groenbone geplant is, met vyf verskillende behandelings van biokoolstof (0t/ha, 1t/ha, 10t/ha, 50t/ha en 200t/ha). Die volgende grondfisiese-eienskappe is ondersoek, naamlik water-stabiele aggregaat formasie, bulkdigtheid en waterhouvermoë, asook die fisiochemiese karakterisering van die sanderige grond en biokoolstof wat gebuik is. Waterverbruik is gedurende die proewe gekontroleer (evapotranspirasie, volumetriese waterinhoud en die biomassa se water verbruiksdoeltreffendheid, BWVD). Die bo- en ondergrondse biomassa, spesifiek die blaareienskappe van die groenboontjie en die strukturele ontwikkeling van die winter koring se wortels, is tydens die oes ondersoek en ontleed. Die volumetriese waterinhoud was betekenisvol, asook hoër vir die 50t/ha en 200t/ha behandelings. Hierdie effek word toegeskryf as gevolg van 'n verandering in die grond se kronkeligheid en porositeit; waar meer meso- en mikroporieë teenwoordig was soos die biokoolstof inhoud toegeneem het. Dieselfde resultate was verkry met die opstelling van ‘n water-retensie kurwe in vitro d.m.v. die Sandboks metode. Bulkdigtheid was slegs betekenisvol verskilled asook aansienlik laer vir die 200t/ha biokoolstof behandelings. Die koring se wortelstelsel het drasties verskil tussen die verskillende bemeste biokoolstof behandelings: die 50t/ha en 200t/ha behandelings het 'n meer komplekse en veselagtige wortelstelsel gevorm (hoër graad van vertakking en dunner wortels was aanwesig) as die 0t/ha, 1t/ha en 10t/ha behandelings. Die effek word toegeskryf aan die toenemende waterhouvermoë, tesame met 'n tekort aan N- en P-beskikbaarheid soos die biokoolstof toedieningshoeveelhede verhoog het. Verskeie blaareienskappe is gemeet vir die groenboon gewasse, maar die blaar stikstof- en koolstof-inhoud, chlorofil inhoud indeks (CII) en koolstof-isotoop fraksionering het die mees interessante bevindinge opgelewer. Die hoogste blaar stikstof-en koolstof-inhoud is gemeet vir die 10t/ha bemeste biokoolstof behandelings. Die blaar chlorofil inhoud het nie beduidend verskil tussen die bemeste biokoolstof behandelings nie, maar daar was egter 'n baie interessante waarneming vir die onbemeste biokoolstof behandelings. ‘n Tendens was aanwesig waar die CII afgeneem het soos die biokoolstof toedieningshoeveelheid ook afgeneem het vir die onbemeste behandelings. Die effek word toegeskryf as gevolg van 'n afname in N-opname deur die plant soos die biokoolstof toedieningshoeveelheid verhoog is en tot gevolg gehad het dat die C/N-verhouding ook toegeneem het, wat gelei het tot N-immobilisasie. Die laagste blaar koolstof-isotoop fraksionering was geassioseer met die 10t/ha bemeste biokoolstof behandelings en is omgekeerd gekorreleerd met BWVD en onderskryf dus die gevolgtrekking dat die 10t/ha biokoolstof behandeling 'n positiewe uitwerking het op die langtermyn waterverbruiksdoeltreffendheid vir groenboontjie plante. Biokoolstof het aggregasie bevorder binne die wortelsone, asook deurgans die waterhouvermoë verhoog en gewasproduksie verbeter. Hierdie bevindinge lewer nuwe inligting oor die effek van biokoolstof op die strukturele ontwikkeling van sanderige grond en die gekombineerde interaksie met biokoolstof toediening en hoe dit wortegroei beïnvloed van winter koring; asook 'n gedetailleerde interpretasie van spesifieke blaareienskappe wat verband hou met die produksie van gewasse vir kommersiële verbouing soos die groenboontjie. Die toediening van biokoolstof by die lae hoeveelhede (ongeveer 1-10t/ha tot op 15 cm diepte) het die opbrengs en waterverbruiksdoeltreffendheid van die gewasse verbeter. Behalwe vir die langtermyn koolstofvaslegging, kan biokoolstof toediening onmiddellike positiewe resultate teweeg bring aangaande die fisiese eienskappe van sandgronde en plantegroei.