Made available in DSpace on 2015-08-20T17:09:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-24. Added 1 bitstream(s) on 2015-08-20T17:26:26Z : No. of bitstreams: 1 000843763.pdf: 3771507 bytes, checksum: 95075b8d207831c0a64fbf7c2f3c81e0 (MD5) / No Brasil e no mundo, a cultura do milho é uma das mais importantes, por ser a base da alimentação animal e utilizado também na alimentação humana. Técnicas sustentáveis de manejo na cultura do milho são necessárias, visando aumento de produtividade, minimizando custos e impactos ambientais. O objetivo deste trabalho foi avaliar diferentes coberturas vegetais (milheto, crotalária, guandu, milheto + crotalária, milheto + guandu e pousio), doses de N (0, 40, 80 e 120 kg ha -1 ) com e sem a inoculação de sementes com Azospirillum brasilense na cultura do milho, cultivado em sistema plantio direto no crescimento e produtividade na região do Cerrado. Foi utilizado delineamento experimental em blocos casualizados em esquema fatorial 6x4x2, constituindo 48 tratamentos, com 4 repetições. O estudo foi realizado na Fazenda Experimental pertencente à Faculdade de Engenharia - UNESP - Campus de Ilha Solteira, localizada no município de Selvíria - MS. O solo do local é do tipo LATOSSOLO VERMELHO Distrófico típico argiloso. A precipitação média anual é de 1.330 mm, a temperatura média anual é de 25 oC e a umidade relativa do ar entre 70 e 80%. Durante a condução do experimento, foram realizadas as seguintes avaliações: massa seca, teores e quantidades acumuladas de N, P e K nas plantas de cobertura; no milho: população inicial e final de plantas, produção de massa seca da parte aérea das plantas, teor de N foliar, índice de clorofila foliar, teores e valores acumulados de N, P e K na planta, altura de plantas e de inserção de espiga, diâmetro de colmo, comprimento de espiga, diâmetro de espiga, massa de mil grãos e produtividade de grãos. As coberturas vegetais, exceto o guandu no primeiro ano e pousio no segundo, produziram quantidade adequada de resíduo para manter o sistema plantio direto na região de Cerrado de baixa altitude. O consórcio milheto + crotalária possibilita quantidades acumuladas de N e K.. / In Brazil and in the world, maize crop is one of the most important because it is the basis of animal feed and also used in human feed. Sustainable techniques of management in maize crop are needed, aiming at increasing yield, reducing costs and environmental impacts. The objective of this study was to evaluate different cover crops (millet, sunn hemp, pigeonpea, millet + sunn hemp, millet + pigeonpea and fallow), N rates (0, 40, 80 and 120 kg ha -1 ) with and without inoculation of seeds with Azospirillum brasilense in maize crop, cultivated in no- tillage system on growth and yield in the Cerrado region. The experimental design was complete randomized blocks in a factorial scheme 6x4x2, constituting 48 treatments, with 4 replications. The study was conducted at the Experimental Farm belonging to the Faculty of Engineering - UNESP (Ilha Solteira), located in Selviria - MS. The soil of the place is a Typical Dystrophic Red Latosol clayey texture. The average annual rainfall is 1.330 mm, the average annual temperature is 25°C and the relative humidity between 70 and 80%. During the experiment, the following evaluations were performed: dry matter, content and accumulated values of N, P and K in cover crops; in maize: initial and final population of plants, production of dry matter of the shoots, leaf nitrogen content, leaf chlorophyll index, content and accumulated values of N, P and K in the whole plant, plant height and of ear insertion, stem diameter, ear length, ear diameter, thousand grain weight and grain yield. The cover crops except the pigeonpea in 2012/13 and fallow in 2013/14 produced adequate amount of residue to keep the no-tillage system in the Cerrado region. The consortium of millet + sunn hemp provided the greater accumulated amount of N and K for both years of cultivation. The great yield of maize grains under pigeonpea residue was due to increase in ear diameter and thousand-grain weight. Thus, the great maize yield ...

Orientador: Orivaldo Arf / Banca: Salatier Buzetti / Banca: Domingos Fornasieri Filho / Resumo: No Brasil e no mundo, a cultura do milho é uma das mais importantes, por ser a base da alimentação animal e utilizado também na alimentação humana. Técnicas sustentáveis de manejo na cultura do milho são necessárias, visando aumento de produtividade, minimizando custos e impactos ambientais. O objetivo deste trabalho foi avaliar diferentes coberturas vegetais (milheto, crotalária, guandu, milheto + crotalária, milheto + guandu e pousio), doses de N (0, 40, 80 e 120 kg ha -1 ) com e sem a inoculação de sementes com Azospirillum brasilense na cultura do milho, cultivado em sistema plantio direto no crescimento e produtividade na região do Cerrado. Foi utilizado delineamento experimental em blocos casualizados em esquema fatorial 6x4x2, constituindo 48 tratamentos, com 4 repetições. O estudo foi realizado na Fazenda Experimental pertencente à Faculdade de Engenharia - UNESP - Campus de Ilha Solteira, localizada no município de Selvíria - MS. O solo do local é do tipo LATOSSOLO VERMELHO Distrófico típico argiloso. A precipitação média anual é de 1.330 mm, a temperatura média anual é de 25 oC e a umidade relativa do ar entre 70 e 80%. Durante a condução do experimento, foram realizadas as seguintes avaliações: massa seca, teores e quantidades acumuladas de N, P e K nas plantas de cobertura; no milho: população inicial e final de plantas, produção de massa seca da parte aérea das plantas, teor de N foliar, índice de clorofila foliar, teores e valores acumulados de N, P e K na planta, altura de plantas e de inserção de espiga, diâmetro de colmo, comprimento de espiga, diâmetro de espiga, massa de mil grãos e produtividade de grãos. As coberturas vegetais, exceto o guandu no primeiro ano e pousio no segundo, produziram quantidade adequada de resíduo para manter o sistema plantio direto na região de Cerrado de baixa altitude. O consórcio milheto + crotalária possibilita quantidades acumuladas de N e K.. / Abstract: In Brazil and in the world, maize crop is one of the most important because it is the basis of animal feed and also used in human feed. Sustainable techniques of management in maize crop are needed, aiming at increasing yield, reducing costs and environmental impacts. The objective of this study was to evaluate different cover crops (millet, sunn hemp, pigeonpea, millet + sunn hemp, millet + pigeonpea and fallow), N rates (0, 40, 80 and 120 kg ha -1 ) with and without inoculation of seeds with Azospirillum brasilense in maize crop, cultivated in no- tillage system on growth and yield in the Cerrado region. The experimental design was complete randomized blocks in a factorial scheme 6x4x2, constituting 48 treatments, with 4 replications. The study was conducted at the Experimental Farm belonging to the Faculty of Engineering - UNESP (Ilha Solteira), located in Selviria - MS. The soil of the place is a Typical Dystrophic Red Latosol clayey texture. The average annual rainfall is 1.330 mm, the average annual temperature is 25°C and the relative humidity between 70 and 80%. During the experiment, the following evaluations were performed: dry matter, content and accumulated values of N, P and K in cover crops; in maize: initial and final population of plants, production of dry matter of the shoots, leaf nitrogen content, leaf chlorophyll index, content and accumulated values of N, P and K in the whole plant, plant height and of ear insertion, stem diameter, ear length, ear diameter, thousand grain weight and grain yield. The cover crops except the pigeonpea in 2012/13 and fallow in 2013/14 produced adequate amount of residue to keep the no-tillage system in the Cerrado region. The consortium of millet + sunn hemp provided the greater accumulated amount of N and K for both years of cultivation. The great yield of maize grains under pigeonpea residue was due to increase in ear diameter and thousand-grain weight. Thus, the great maize yield ... / Mestre

Cover crops not only improve soil conditions, but can also suppress weed growth. In a field experiment the influence of two cover crops, Secale cereale (stooling rye), and Lolium multiflorum (annual ryegrass), on the growth of Zea mays (maize) and C. esculentus (yellow nutsedge) was compared to the latter crop and weed’s growth at three control treatments which involved weed residues left on the soil surface, application of herbicides and weed control by hoeing. Maize emergence and growth were delayed in the presence of residues of both cover crop species, especially in annual ryegrass residues. C. esculentus growth was significantly inhibited in the area between the maize planting rows by the cover crops for the first 14 days after maize emergence, but this growth suppressing effect diminished after 28 days. In a controlled environment study, the influence of the same cover crops, together with Avena sativa (oats) and three cultivars of annual ryegrass were evaluated. Maize and C. esculentus growth were suppressed, especially by the root residues of the cover crops with the annual ryegrass cultivar ‘Midmar’ being the most suppressive. Chemical analysis of the leachate of root residues indicated the presence of phenolic acids and benzoxazolin-2(3 H)-one (BOA). It is suggested that weed growth could be reduced by the allelochemicals leached from cover crop residues but in order to achieve prolonged, effective weed control the combination of mulch retained on the soil surface and the application of herbicides will required. In an integrated weed management approach a possible reduction in the type and number of herbicide applications required for effective weed control, could be implemented. / Thesis (PhD)--University of Pretoria, 2012. / Plant Production and Soil Science / unrestricted

Limited photosynthetically active radiation (PAR) can reduce interseeded cover crop growth in corn (Zea mays L.). Two experiments in North Dakota evaluated the effect that hybrid relative maturity (RM), row width, and cover crop planting date have on cereal rye (Secale cereale L.) and winter camelina [Camelina sativa (L.) Crantz.] establishment when interseeded into 80 and 89 RM hybrids at V7 and R4 growth stages in 56- and 76 cm corn row widths. Cover crop biomass was typically less than 100 kg ha-1. In the following spring larger amounts of PAR beneath the 80 RM hybrid increased cover crop biomass by 20.8 kg ha-1. Cover crop biomass tended to be greater in the 76 cm row width but was not significantly different from the 56 cm width. Cover crops decreased residual soil nitrate by 6.0 kg ha-1 in the fall and by 15.6 kg ha-1 in the spring.

The occurrence of herbicide resistance weeds across the southern United States has been increasing. Research is needed to develop alternative control measures, while supporting sound agronomic practices. Greenhouse and field studies were conducted to evaluate cereal cover cropping techniques along with novel herbicides to determine their value for Mississippi growers. Field studies were performed to determine which combination of cereal cover crops (cereal rye, wheat and oats) and residual herbicides (S-metolachlor + metribuzin, S-metolachlor + fomesafen, pendimethalin, flumioxazin, sulfentrazone + metribuzin and pyroxasulfone + flumioxazin) would maximize soybean yield in the presence of weeds. Cereal cover crop termination methods were evaluated and a partial budget was generated to examine the total costs of growing soybeans utilizing cereal cover crops and residual herbicides. Residual herbicide applications averaged across all cereal cover crops controlled Amaranthus spp. greater than 89% by 28 DAT. Control by the cover crops alone was 67% for of Amaranthus spp. In all cereal species tested, cutting the cover crops 10 cm above the soil and leaving the residue reduced weed numbers compared to other termination methods. However, high production and implementation costs may prevent widespread adoption of cereal cover crops and residual herbicides in Mississippi. Aminocyclopyrachlor (AMCP) is a synthetic auxin herbicide currently labeled for non-crop use, but has characteristics which may make it useful as a preplant burndown (PPB) herbicide. The application of AMCP prior to planting of corn and cotton were evaluated and carryover effects to soybean were also evaluated. Tank mix combinations of AMCP with residual herbicides (rimsulfuron, flumioxazin, pyroxasulfone, pyroxasulfone+ flumioxazin and atrazine) were also evaluated. A rate titration of AMCP and its impacts on crop species were evaluated in the greenhouse. Corn showed tolerance to AMCP except at 0.28 kg ai ha-1 applied prior to planting. Cotton was sensitive to AMCP as rate increased closer to the planting date, but response depended upon soil texture. AMCP impacts on soybean showed greater sensitivity (90% injury) then all other species evaluated. Due to potential impacts on soybean and cotton, AMCP is not a potential PPB for use in Mississippi.

Mid-southern USA soybean [Glycine max (L.) Merr.] producers are being pushed to increase adoption of conservation tillage systems as a means of increasing the application efficiency of gravity flow irrigation systems. This research was conducted to determine whether the efficiency of furrow-irrigation systems could be manipulated through conservation tillage systems while maintaining soybean productivity and profitability. Three experiments were conducted near Stoneville, MS on a Dubbs silt loam (Fine-silty, mixed, active, thermic Typic Hapludalfs) to determine the effects of reducing tillage and increasing ground cover residues on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs. In experiment 1, transitioning from conventional tillage to a conservation tillage system had no adverse effect on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, or net returns above specified costs when subsoiling was included. For experiment 2, replacing subsoiling with a cereal rye or tillage radish cover crop in a conservation tillage system either had no effect or reduced irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs up to 41%. In experiment 3, independent of cover crop, reducing tillage to only furrow creation had no adverse effect on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs relative to a conservation tillage system with subsoiling. Conservation tillage systems that include subsoiling maximize irrigation application efficiency and irrigation water use efficiency while minimizing adverse effects on yield and net returns relative to conservation tillage systems that further reduce tillage and/or increase ground coverage with cover crops. Our data indicate that soybean producers in the mid-southern USA maximize furrow-irrigation functionality, yield, and profitability while minimizing risk by transitioning from a conventional tillage system to a conservation tillage system with subsoiling.

Cover crops and composted broiler litter (CBL) are two organic methods used to improve soils and organic vegetable production. The objectives of this study included determining the extent summer cover crops and CBL alter nutrient availability in soil, determining how summer cover crops and CBL influence fall vegetable crops in organic production systems and identifying which cover crops/ CBL combinations improve fall vegetable crop production best. Four cover crops were tested: sunn hemp (Crotalaria juncea), sesame (Sesamum indicum), sorghum sudan grass (Sorghum X drummondii) and a sunn hemp + sesame blend, in combination with four composted broiler litter rates: 0, 2,800, 5,600, 11,200 kg.ha-1 for two years. Few differences were seen among cover crop treatments except for the sorghum sudan grass treatment, which had negative effects on fall broccoli production unless combined with CBL. The CBL increased nutrient availability, percent organic matter, pH and broccoli yield as the rate increased.

No description available.

Cover crops (CC) can contribute to production in pastures, but the diversity of CC mixtures and defoliation frequency (DF) may alter productivity. A 2-yr experiment conducted at Raymond, MS, quantified CC × DF effects on forage mass (FM) and nutritive value of winter CC and subsequent summer hay production. Treatments were factorial combinations of 10 CC (using several species of grasses, legumes, and brassicas) and three DF (harvested every 4 or 8-wk or cut and left as mulch) in a split-plot arrangement of a randomized complete block design experiment with three replications. Generally, mixtures with legumes had greater FM and better nutritive value. Summer hay production did not respond to difference in CC composition, however, harvesting of CC reduced summer hay but increased year-long FM. These results suggest that CC when harvested can contribute to forage production with improved nutritive value and can increase year-long FM, but summer hay production can benefit when the CC is left as mulch.

Aquifer resources in the mid-southern USA are declining because of irrigation water use in row crops. This study assesses the effectiveness of conservation tillage and cover cropping systems in reducing irrigation water use while improving or maintaining cotton yield and profitability. The effects of different tillage and cover crop cropping systems on soil moisture, irrigation water use, cotton yield, and profitability were investigated near Stoneville, MS on a Dubbs silt loam (fine-silty, mixed, active, thermic Typic Hapludalfs) and a Bosket very fine sandy loam (fine-loamy, mixed, active, thermic Mollic Hapludalfs). Reducing tillage reduced irrigation water use by 3.3 cm ha-1, and adding cover crops to conservation tillage practices further reduced irrigation water use to nearly zero (0.5 cm ha-1). Before irrigation, the conventionally-tilled soils had at least 59% greater soil tension (less soil moisture; P>F = 5.41×10-8) than all other conservation practices. Soil moisture was higher where cover crops were sown (20 kPa) than where treatments were winter fallowed (34 kPa). Prescribed irrigation to replenish treatments that reached the irrigation threshold (80 kPa) did not change the trend in soil moisture among treatments. The use of any conservation practice improved season-long soul moisture by at least 19 kPa (P>F = 3.8×10-12). Cover crops infiltrated 13% (P>F = 0.003) more rainwater than winter fallow, and subsoiling improved precipitation infiltration by 16% over non-subsoiled systems (P>F = 0.009). Lint yields were similar across all treatments in 2021 and 2022, but they were 222 kg ha-1 less (P>F = 0.029) in treatments with a cover crop than the control in 2023. The lowest costs acre-1 were realized when the no-seedbed-tillage with winter fallow treatment was used. Utilizing a cover crop reduced irrigation expenses by $7.40 acre-1 compared to the conventionally-tilled control. However, gross returns were reduced by $113 acre-1 where cover crops were sown and reduced overall net returns by $201 acre-1. The strip-tillage and no-seedbed tillage systems with winter fallow reduced overall risk of production when compared to the conventional control and treatments with a cover crop. Conservation systems successfully reduced irrigation water use, but systems with a cover crop may not be economically viable because of low yields and high costs.