Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-08-17T18:27:17Z No. of bitstreams: 1 2000 - Pedro Nilson Alves Berto.pdf: 654186 bytes, checksum: ef66a21a2e6b0ca326c348f84fb13d3e (MD5) / Made available in DSpace on 2016-08-17T18:27:17Z (GMT). No. of bitstreams: 1 2000 - Pedro Nilson Alves Berto.pdf: 654186 bytes, checksum: ef66a21a2e6b0ca326c348f84fb13d3e (MD5) Previous issue date: 2000-12-12 / CHAPTER I: In a Inceptisol soil, at Santa Cruz Sugar Mill, Campos dos Goytacazes/RJ, an experiment was conducted with the purpose to evaluate, during the cycle of second ratoon answers to the application of sugarcane agroindustry wastes, in consitions of harverst management with and without previous burning, using the growth quantitative analysis and utilizing the RB72454 sugarcane variety. The experimental field was planted in April 1992. The plant cane cut ocurred in July 1993. The first ratoon was harvested in August 1994, when the test was reinstalled to evaluation in the second ratoon, which harvest was in September 1995. The tested treatment were: 1 = CC = raw cane; 2 ? CC + TF = raw cane + 30 t.ha-1 of filter cake; 3 ? CC + TF + B = raw cane + 20 tons of filter cake ha-1 + 10 t.ha-1 of bagasse; 4 ? CQ = burned cane; 5 ? CQ + TF = burned cane + 30 t.ha-1 of filter cake; 6 ? CQ + TF + B = burned cane + 20 t.ha-1 of filter cake + 10 t.ha-1 of bagasse. The physiological rates discussed and interpreted were: a) Number of stalks by linear meter; b) Stalk height (m); c) Total biomass (g.m-2 soil); d) Leaf area index (m2 leaf. m-2 soil); e) Growth tax of the cultural (g.m-2 leaf. day-1); f) Liquid assimilation tax (g.m-2 leaf.day-1); g) Leaf nitrogen concentration; h) Stalk nitrogen concentration. The results allowed the following conclusions: 1) The application of the sugar agroindustry wastes (filter cake and bagasse) in areas harvest with or without burning, didn?t increased the stalks number and canes height. 2) The fact of not have significant differences to the stalks number rates by linear meters and canes height, reflected directly in a not statistical difference among the evaluated treatments, beeing relative a industrial stalks final productivity in t.ha. 3) The value of total biomass, obtained in the various treatments, was very low, mainly in function of hydric deficit ocurred in the period of the development of the experiment. 4) O I.A.F. (leaf area index), showed little significant changes in the first samples (second, fourth and sixth months), with higher values to burning treatments, in function of a higher stalks number by meter found in this parcels. 5) The straw index calculated (20, 6 t.ha-1) affected the ratoon budding, lowing the stalks population. 6) The leaf area index stayed lower than that considered ideal to the development of a productive sugarcane plantation, correlating with the law productivity obtained, beeing a good physiological parameter to the estimation of a sugarcane?s production. 7) The growth tax of the culture showed the highest values between 120 e 240 days after cut, similar to all treatments during the vegetative development cycle and coincided to the highest foliar area index. 8) The liquid assimilation tax was affected by the hydric stress in the period of the maximum growth of the culture. 9) The nitrogen leafs concentration, as the nitrogen stalks concentration didn?t show differences among the treatments. The fact that the soil studied was a Inceptisol soil, with great natural fertility and that ocurred a great hydric stress during the culture cycle, may have equalized the answers. -------------------------------------------------------------------- CHAPTER II: In a Inceptisol soil of Santa Cruz sugar mill; located at Campos dos Goytacazes,RJ, an experiment was conducted to evaluate the influence, in the chemical and biological properties of the soil, during the sugar cane second ratoon, of the sugar industry wastes (filter cake and bagasse) applied into experimental parcels harvested with and without previous burning of the cane. The experimental field was planted in April 1992. The harvest of the cane ocurred in July 1993. The first 1994, ratoon was harvested in August when the experiment was reinstalled for evaluation in the second ratoon, which harvest was done in September 1995. The tested treatments were: 1= CC= raw cane; 2- CC+TF= raw cane + 30 t.ha -1 of filter cake; 3-CC+TF+B= raw cane + 20 tons of filter cake ha-1 + 10 t. ha-1 of bagasse; 4-CQ= burned cane; 5- CQ +TF= burned cane + 30 t ha-1 of filter cake; 6-CQ + TF + B= burned cane + 20 t.ha-1 of filter cake + 10 T.ha-1 of bagasse. The parameters discussed and interpreted were: a) manufacturable stalks productivity in t.ha-1; b) Sugar production in t Pol ha -1; c) microbial soil biomass-carbon in mgCg -1 of soil; d) agroindustrial wastes effect among treatments on the productivity of second and the third curts of the in t.sugarcane ha-1; e) treatments effects on soil chemical properties; f)straw index determination. The results allowed the following conclusions: 1- The application of the sugar agroindustry wastes (filter cake and bagasse), in the sugar cane fields harvested with or without burning, didn`t result in increasing of productivity, in t.ha-1 or in t.ha-1. 2- Raw cane treatments, that received industrial wastes, showed expressive higher values of BMS-C, in comparison with burned cane treatments, mainly in raw cane treatment with filter cake. 3- The Inceptisol soil, may have facilitaded the similarity of the production results (t cane ha-1), due to the its high natural fertility. 4- Straw index, equivalent to 20,6 t. straw ha, may have affected the ratoon budding of the raw cane treatments. 5- generally speaking, the soil chemical properties studied haven`t been modified when the treatments are compared. / CAP?TULO I: Em solo Cambissolo eutr?fico, da usina Santa Cruz, RJ, foi conduzido experimento objetivando avaliar, durante ciclo de segunda soca (terceiro corte da cultura da cana-de-a??car), respostas ? aplica??o de res?duos da agroind?stria a?ucareira, em condi??es de manejo de colheita com e sem pr?via queima, utilizando-se da an?lise quantitativa de crescimento e empregando-se a variedade RB72454. O campo experimental foi plantado no m?s de abril de 1992. O corte da cana-planta ocorreu em julho de 1993. A primeira soca foi colhida em agosto de 1994, ocasi?o em que se reinstalou o ensaio para avalia??o na Segunda soca ou terceiro corte, cuja colheita aconteceu em setembro de 1995. Os tratamentos efetuados foram: 1 ? CC = cana-crua; 2 ? CC + TF = cana crua + 30 toneladas. ha-1 de torta de filtro; 3 ? CC + TF + B = cana-crua + 20 toneladas de torta de filtro . ha-1 + 10 toneladas . ha-1 de baga?o; 4 ? CQ = cana queimada; 5 ? CQ + TF = cana queimada + 30 toneladas . ha-1 de torta de filtro; 6 ? CQ + TF + B = cana queimada + 20 toneladas . ha-1 de torta de filtro + 10 toneladas . ha-1 de baga?o. Os par?metros fisiol?gicos discutidos e interpretados foram: a) n?mero de colmos por metro linear; b) altura do colmo (m); c) fitomassa total (g.m-2 solo); d) ?ndice de ?rea foliar (m2 folha . m-2 solo); c) taxa de crescimento da cultura (g. m- 2 solo.dia-1); f) taxa de assimila??o l?quida (g.m-2 folha.dia-1); g) concentra??o de nitrog?nio nas folhas; h) concentra??o de nitrog?nio no colmo. Os resultados obtidos permitiram as seguintes conclus?es: 1. A aplica??o dos res?duos da agroind?stria a?ucareira (torta de filtro e baga?o), nas ?reas colhidas com e sem queima, n?o resultou em aumento no n?mero de colmos por metro linear e nem na altura das canas. 2. O fato de n?o haver diferen?as significativas para os par?metros n?mero de colmos por metro linear e de altura das canas, refletiu-se diretamente na n?o diferen?a estat?stica entre os tratamentos avaliados, no que se refere ? produtividade final dos colmos industrializ?veis em t.ha-1. 3. O valor da fitomassa total, obtida nos diversos tratamentos, apresentou-se muito baixo, em fun??o principalmente do d?ficit h?drico ocorrido no per?odo de condu??o do experimento. 4. O I.A.F. (?ndice de ?rea foliar), apresentou varia??es significativas nas primeiras amostragens (segundo, quarto e sexto meses), com valores maiores para os tratamentos com queima, em fun??o de maior n?mero de colmos por metro encontrado nestas parcelas. 5. O ?ndice de palhi?o calculado (20,6 t.ha-1) afetou a brota??o de soqueiras dos tratamentos com cana crua, prejudicando a popula??o de colmos. 6. O ?ndice de ?rea foliar ficou abaixo do considerado ideal para a forma??o de lavoura produtiva, correlacionando-se com a baixa produtividade obtida, mostrando-se como um bom par?metro fisiol?gico para estimativa da produ??o canavieira. 7. A taxa de crescimento da cultura apresentou valores m?ximo entre 120 e 240 dias ap?s o corte, foi semelhante para todos tratamentos ao longo do ciclo de desenvolvimento vegetativo e coincidiu com os per?odos de ?ndice de ?rea foliar m?ximos. 8. A taxa de assimila??o l?quida foi afetada pelo estresse h?drico no per?odo de m?ximo crescimento da cultura. 9. A concentra??o de nitrog?nio nas folhas, assim como a concentra??o de nitrog?nio nos colmos, n?o apresentou diferen?as entre tratamentos. O fato de o solo estudado ser um Cambissolo eutr?fico, com alta fertilidade natural e de ter ocorrido forte stress h?drico durante o ciclo da cultura, pode ter nivelado as respostas. -------------------------------------------------------------------- CAP?TULO II: Num Cambissolo eutr?fico da usina Santa Cruz, localizada no munic?pio de Campos dos Goytacazes, RJ, foi conduzido experimento objetivando avaliar, durante ciclo de segunda soca (terceiro corte) da cultura da cana-de-a??car, o efeito de res?duos da fabrica??o do a??car, (torta de filtro e baga?o), aplicados em parcelas experimentais posteriormente colhidas com cana crua e com cana sem queima, nas suas propriedades qu?micas e biol?gicas. O campo experimental foi plantado no m?s de abril de 1992. O corte da cana-planta ocorreu em julho de 1993. A primeira soca foi colhida em agosto de 1994, ocasi?o em que se reinstalou o ensaio para avalia??o na segunda soca ou terceiro corte, cuja colheita aconteceu em setembro de 1995. Os tratamentos efetuados foram: 1 ? CC = cana crua; 2 ? CC + TF = cana crua + 30 toneladas.ha-1 de torta de filtro; 3 ? CC + TF + B = cana crua + 20 toneladas de torta de filtro.ha-1 + 10 toneladas.ha-1 de baga?o; 4 ? CQ = cana queimada; 5 ? CQ + TF = cana queimada + 30 toneladas .ha-1 de torta de filtro; 6 ? CQ + TF + B = cana queimada + 20 toneladas.ha-1 de torta de filtro + 10 toneladas.ha-1 de baga?o. Os par?metros discutidos e analisados foram: a) produtividade de colmos industrializ?veis em t.ha-1; b) produ??o de a??car em t POL.ha-1; c) biomassa microbiana do solo-carbono em mgC.g-1 de solo; d) efeito dos res?duos agroindustriais entre tratamentos, nas produtividades dos segundo e terceiro cortes, em t cana.ha-1; e) efeito dos tratamentos sobre as propriedades qu?micas do solo; f) determina??o do ?ndice do ?palhi?o?. Os resultados obtidos permitiram as seguintes conclus?es: 1 ? A aplica??o dos res?duos da agroind?stria a?ucareira (torta de filtro e baga?o), nos canaviais colhidos com e sem queima, n?o resultou em aumentos de produtividade, quer seja em t cana.ha-1 ou em t pol.ha-1. 2 ? Os tratamentos com cana crua que receberam res?duos industriais, apresentaram valores significativamente maiores de BMS-C, em compara??o ao tratamento cana queimada. Houve uma maior propor??o de carbono imobilizado na biomassa microbiana do solo, principalmente no tratamento cana crua com torta de filtro adicionada. 3 ? O tipo de solo estudado, Cambissolo Eutr?fico, pode ter facilitado a semelhan?a dos resultados de produ??o (t cana.ha-1), em fun??o de sua alta fertilidade natural. 4 ? O ?ndice de Palhi?o, equivalente a 20,6 t.ha-1 de palha, pode ter afetado a brota??o de soqueiras dos tratamentos com cana crua. 5 ? De modo geral, as propriedades qu?micas do solo estudadas n?o foram alteradas quando se compararam os tratamentos.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-09-11T19:30:41Z No. of bitstreams: 1 2017 - Marcius Nei Zanin Cesar.pdf: 3447328 bytes, checksum: 098490a3674208d8609db17b18d3c285 (MD5) / Made available in DSpace on 2018-09-11T19:30:41Z (GMT). No. of bitstreams: 1 2017 - Marcius Nei Zanin Cesar.pdf: 3447328 bytes, checksum: 098490a3674208d8609db17b18d3c285 (MD5) Previous issue date: 2009-04-30 / Cap. I The aim of this work is to evaluate the agronomic behavior of different legume species under cerrado conditions in Mato Grosso do Sul. Seven experiments were carried out, all of them in the experimental field of the (Ag?ncia de Desenvolvimento Agr?rio e Extens?o Rural de MS), (Agency of rural development and extension of MS). Two of these experiments referred to the performance of legumes evaluation. The first experiment was carried out during the Spring- Summer period, and the second one during the Fall- Winter period. The treatments were constituted by the legume species (Crotalaria juncea, Crotalaria ochroleuca, Crotalaria mucronata, Crotalaria reviflora, Mucuna pruriens, Mucuna aterrima, Cajanus cajan (L.) Millsp Cv Fava larga and Cv IAPAR Arat? 43 an?o, Canavalia ensiformes and Canavalia brasiliensis). The third experiment was carried out to determine the dry phytomass decomposition rate and the nitrogen release of the species that were evaluated; this happened during the Fall-Winter period, and the treatments were the mulching of the legumes cited above, except C. breviflora, which was severely attacked by Fusarium sp. The experimental design adopted was randomized blocks, with eleven treatments and nine harvest dates disposed with four replicates. The forth and the fifth experiments were carried out in the subsequent year, their aim was qualifying the Biological Nitrogen Fixation (hereinafter called BNF) and determining the isotope discrimination value ?B value?; their treatments were seven legume species previously selected due to their performances on the former experimental actions and three checks, Brachiaria decumbens, Helianthus annuus, and Zea mays cv BR 106, disposed in randomized blocks with four replicates. The sixth and the seventh experiments were carried out to evaluate the performance of the cabbage cv Astrus under organic management in no-tillage system. The treatments of the sixth experiment were maize-velvet bean intercrop. The later was sown in five different times after maize germination, mucuna alone, maize alone, spontaneous vegetation, and cultivation with conventional tillage of the soil. The treatments of the seventh experiment were maize intercropped with Crotalaria juncea, the latter was slashed, slashed and pruned, maize with basic fertilizer, maize with basic and dressing fertilizers, crotalaria alone, maize alone, spontaneous vegetation, and cultivation with conventional tillage of the soil. The experimental design adopted for both experiments was randomized blocks. The evaluation of the aerial phytomass production was determined when the legume species flowered and when the non-legume ones underwent the grain filling process. The quantification of BNF and the determination of the B value were estimated by using natural abundance 15N and the 15N dilution technique. Functional growth analyses were also carried out as well as soil cover rates, digestion time of the plant tissues, and the phytosociology were determined. On the sixth and seventh experiments the green manure contributions on the agronomic behavior of the cabbage cultivated in no-tillage system under organic management were evaluated. The results obtained have demonstrated the viability for the cultivations of these legume species at the Cerrado Biome, with the contribution of the BNF varying between 75 and 85% of the nitrogen found in the plant tissue originating from the air. They have also demonstrated the viability of using C. juncea and velvet bean when both are intercropped with maize in the mulching formation to the organic cultivation of the cabbage in no-tillage system Cap. II Two experiments were carried out to evaluate the agronomic behavior of legume species in which several components of plant growth were evaluated, such as aerial phytomass production, soil cover rate, seed production, besides phytosociology and in situ decomposition rate under cerrado conditions in Mato Grosso do Sul in two periods of the year. One experiment was carried out during the Spring-Summer period and the other one was carried out during the Fall-Winter period. Both experiments were carried out at the Centro de Pesquisa da Ag?ncia de Desenvolvimento Rural e Extens?o Rural de Mato Grosso do Sul (Mato Grosso do Sul Research center of the Agency of rural development and extension), in Campo Grande ? MS. The experimental design adopted for both was randomized blocks, formed by eleven treatments made up by the species C. juncea, C. ochroleuca, C. mucronata, C. spectabilis, C. breviflora, Mucuna aterrima, Mucuna pruriens, Canavalia brasiliensis, Canavalia ensiformis, Cajanus Cajans cv ?IAPAR an?o?, and Cajanus Cajans cv. giant broad bean. The agronomic behavior of the species that were studied was evaluated by the analysis of the stem and the leaf separately. It was observed that the aerial phytomass productions differed significantly with the species of the genus Crotalaria, showing the best results. Crotalaria juncea stands out with 14.16 Mg ha-1, followed by the Cajanus cajan cv. Fava larga with 11.58 Mg ha-1; there were no significant differences among the species of prostrate habit, mucunas and Brazilian jackbean (Canavalia brasiliensis). The later obtained 3.56 Mg ha-1 and the former did 2.85 Mg ha-1. Regarding seed production, the best performances were obtained during the Fall-Winter period for all legume species, except jack bean and feij?o-bravo (Capparis flexuosa), both obtained similar performances on the two periods of sowing, probably because they might be more tolerant to the drought stress. Regarding the decomposition rate, the results have revealed that the decomposition constants and the residue half-lives had different behaviors on the species that were studied; the Crotalaria species obtained higher decomposition rates when compared to the other species, differentiated behaviors were also noticed on the stem and on the leaf. The C. juncea, jack bean, and the two species of mucuna obtained higher soil cover rate, which reflected a higher suppression of spontaneous plants Cap. III Two experiments related to the quantification of BNF and the determination of the isotope discrimination, ?B value?, in legume species previously selected were simultaneously carried out in the experimental field of the AGRAER-MS, in Campo Grande-MS, during the Spring/Summer period in the 2005/2006 year of production. The experimental design adopted was randomized blocks, formed by ten treatments made up by the species C. juncea, C. ochroleuca, C. mucronata, C. spectabilis, velvet bean, Brazilian jackbean, and Pigeon pea; there have been also, as checks, Sunflower, Maize, and Brachiaria species. The aerial phytomass productions were determined when each legume species flowered and when the non-legume ones underwent the grain filling process. With the samples of legumes and check plants, the quantities of N and the BNF were estimated by using the 15N dilution technique. Afterwards, when the BNF values were known, they were applied to the equation used in natural abundance 15N with the aim of estimating the B value. Regarding the aerial phytomass production, the Pigeon pea had the best performance, followed by the C. ochroleuca, reaching averages of 16.24 Mg ha-1 against 14.44 Mg ha-1. The legume species behaved similarly to the amount of accumulated nitrogen; the Pigeon pea, C. ohcroleuca, and C. mucronata reached values of 346.57 kg ha-1, 333.25 kg ha-1, and 277.35 kg ha- 1 respectively, and they deserve a distinction. Regarding the %BNF, it was observed that the 15N dilution technique could not be applied in all the species that were studied since the cycle of most legumes species was different from the checks; in this way, the checks were not appropriate because the technique demands that legumes and checks grow simultaneously and under the same conditions. However, to the varieties which were more precocious that the checks, the BNF value must be at least between 73 to 87%. Just on the specie C. mucronata it was possible to estimate the BNF and the B value with the rigor that the applied isotopic methodologies demand. The B value of this specie was -3.69. Cap. IV The aim of this study is to evaluate the agronomic behavior of the cabbage in no-tillage system under organic management and the contribution of the prior cultivation of two legumes with different growing habits intercropping with maize in the mulching formation. Both experiments were carried out in the experimental field of AGRAER-MS, in Campo Grande-MS. The first experiment was the maize-C. juncea intercrop, the latter was managed, slashed, pruned, and slashed afterwards; besides the cultivation of single maize, single C. juncea, cultivation with conventional tillage of the soil with and without fertilization with equivalent amounts of 100 Kg N ha-1 at planting and sidressed 30 days after the maize cultivation, making up eight treatments with four replications in randomized blocks. The dry matter productions in the aerial part of the cover crops and the spontaneous vegetation were evaluated. Agronomic characteristics that were evaluated on the cabbage: productivity, commercial standard, fresh and dry weight, besides the dry phytomass of the prior cultivation. On this experiment it was possible to verify better yields regarding the fresh weight and head diameter when we used single, pruned C. juncea maize with basic fertilizer, and maize with base and dressing fertilizers, reaching a fresh weight over 1.0 Kg and heads diameter over 10 cm. Regarding maize and cabbage productivity, they were not influenced by the different kinds of intercrop systems; there were no significant statistic difference of treatments, which also reflected on the dry matter production of the prior cultivations. On the second experiment, the experimental design which was adopted was randomized blocks, with nine treatments and four replicates. The treatments were: maize-velvet bean intercrop, the later was planted in five different times: after the maize germination, maize alone, mucuna alone, cultivation with conventional tillage of the soil, and fallow with spontaneous vegetation, making up a total number of nine treatments. The parameters that were evaluated were similar to the ones of the former experiment.The cabbage production showed the most promising yield 2.06 Kg of head average weight and when cultivated as a sequential crop to the maize-velvet bean intercrop sown 15 days after the maize germination, differing significantly from the other treatments. When we analyzed the maize productivities, we noticed fall of productivity around 29% when it was intercropped with velvet bean at 15 and 30 days after its germination when it was compared to the other prior cultivations in which the intercrop system was used. / Cap. I O presente trabalho teve como finalidade avaliar o comportamento agron?mico de diferentes esp?cies de leguminosas nas condi??es do cerrado de Mato Grosso do Sul. Foram conduzidos sete experimentos, todos no campo experimental da Ag?ncia de Desenvolvimento Agr?rio e Extens?o Rural de MS, sendo que dois deles foram referentes ? avalia??o do desempenho das leguminosas. O primeiro foi instalado no per?odo de primavera-ver?o e o segundo no outonoinverno. Os tratamentos foram constitu?dos das esp?cies de leguminosas Crotal?ria juncea, Crotal?ria ochroleuca, Crotal?ria mucronata, Crotal?ria reviflora, Mucuna pruriens, Mucuna aterrima, Cajanus cajan (L.) Millsp cv Fava larga e Cv IAPAR Arat? 43 an?o, Canavalia ensiformes e Canavalia brasiliensis. O terceiro experimento foi realizado para determinar a taxa de decomposi??o da fitomassa seca e libera??o de nitrog?nio das esp?cies avaliadas, realizado no per?odo de outono-inverno, com os tratamentos constituindo-se da palhada das leguminosas descrita acima, exceto C. breviflora, pois a leguminosa sofreu ataque severo de Fusarium sp. O delineamento experimental foi em blocos ao acaso, com onze tratamentos e nove ?pocas de coleta distribu?dos em quatro repeti??es. O quarto e o quinto experimentos foram realizados no ano subsequente e tiveram como finalidade quantificar a Fixa??o Biol?gica de Nitrog?nio (FBN) e determinar o valor de discrimina??o isot?pica ?Valor B?, tendo como tratamentos sete esp?cies de leguminosas previamente selecionadas pelos seus desempenhos nas a??es experimentais anteriores e tr?s testemunhas, Brachiaria decumbens, Helianthus annuus e Zea mays cv BR 106, dispostos em blocos ao acaso com quatro repeti??es. O sexto e o s?timo experimentos foram conduzidos para avaliar o desempenho do repolho cv Astrus sob manejo org?nico em sistema plantio direto, sendo que o sexto experimento teve como tratamentos cons?rcio milho x mucuna cinza, sendo esta semeada em cinco ?pocas diferentes, ap?s germina??o do milho, mucuna em monocultivo, milho em monocultivo, vegeta??o espont?nea e cultivo com preparo convencional do solo. O s?timo experimento teve como tratamentos milho consorciado com Crotal?ria juncea, sendo esta ro?ada, ro?ada e podada, milho com aduba??o de base, milho com aduba??o de base e cobertura, crotal?ria em monocultivo, milho em monocultivo, vegeta??o espont?nea e cultivo com preparo convencional do solo. O delineamento experimental adotado em ambos os experimentos foi o de blocos ao acaso. A avalia??o da produ??o de fitomassa a?rea foi determinada por ocasi?o do florescimento para as esp?cies de leguminosas e de enchimento de gr?os para as n?o-leguminosas. A quantifica??o da FBN e determina??o do valor ?B? foram estimadas utilizando-se a t?cnica de abund?ncia natural 15N e da dilui??o isot?pica de 15N. Foram tamb?m realizadas an?lises funcionais de crescimento, bem como determinadas as taxas de cobertura do solo, tempo de decomposi??o dos tecidos vegetais e a fitossociologia. No sexto e no s?timo experimentos, foram avaliadas as contribui??es da aduba??o verde no desempenho agron?mico do repolho cultivado em sistema de plantio direto, sob manejo org?nico. Os resultados obtidos demonstraram a viabilidade do cultivo destas leguminosas no bioma cerrado, com a contribui??o da FBN, variando entre 75 e 85% do nitrog?nio encontrado no tecido vegetal proveniente do ar. Tamb?m, demonstraram a viabilidade do uso da C. juncea e M. cinza quando cultivadas em cons?rcio com milho para obten??o de palhada ao cultivo org?nico do repolho em sistema plantio direto. Cap. II Dois experimentos foram conduzidos para avaliar o comportamento agron?mico de esp?cies de leguminosas, onde foram avaliados diferentes componentes do crescimento vegetal, como produ??o fitomassa a?rea, taxa de cobertura de solo, produ??o de sementes, al?m da fitossociologia e taxa de decomposi??o ?in situ?, nas condi??es do cerrado de Mato Grosso do Sul, em duas ?pocas do ano. Os experimentos foram conduzidos no Centro de Pesquisa da Ag?ncia de Desenvolvimento Agr?rio e Extens?o Rural de Mato Grosso do Sul, localizado em Campo Grande - MS, sendo um no per?odo de primavera-ver?o e outro no outono-inverno. Em ambos, o delineamento experimental adotado foi o de blocos ao acaso, formado de onze tratamentos constitu?dos das esp?cies C. juncea, C. ochroleuca, C. mucronata, C. spectabilis, C. breviflora, Mucuna aterrima, Mucuna pruriens, Canavalia brasiliensis, Canavalia ensiformis, Cajanus Cajans cv. IAPAR an?o e Cajanus Cajans cv. fava larga gigante. O comportamento agron?mico das esp?cies estudadas foi avaliado analisando-se separadamente haste e folha. Observou-se que as produ??es de fitomassa a?rea diferiram de forma significativa com as esp?cies do g?nero crotal?ria, obtendo-se melhores desempenhos. Destacam-se a Crotal?ria juncea com 14,16 Mg ha-1, seguida do Guandu cv fava-larga com 11,58 Mg ha-1; entre as esp?cies de h?bito prostrado, n?o houve diferen?as significativas, mucunas e o feij?o-bravo-do Cear?, sendo que esse obteve 3,56 Mg ha-1 contra 2,85 Mg ha-1 da M. preta. Com rela??o ? produ??o de sementes, os melhores desempenhos foram obtidos no per?odo de outono-inverno para todas as leguminosas, com exce??o do feij?o-de-porco e feij?o-bravo, que obtiveram desempenhos semelhantes nas duas ?pocas de semeadura, provavelmente, por serem mais tolerantes ao estresse h?drico. No tocante ? taxa de decomposi??o, os resultados revelaram que as constantes de decomposi??o e tempo de meia-vida tiveram comportamentos diferentes para as esp?cies estudadas, com esp?cies de crotal?ria obtendo maiores velocidades de decomposi??o quando comparadas ?s demais esp?cies, notou-se tamb?m comportamentos diferenciados para haste e folha. A C. juncea, feij?o de porco e as duas esp?cies de mucuna obtiveram maior taxa de cobertura de solo, o que refletiu em uma maior supress?o da vegeta??o de ocorr?ncia espont?nea Cap III Foram conduzidos simultaneamente dois experimentos relacionados ? quantifica??o da FBN e determina??o do valor de discrimina??o isot?pica, valor ?B?, em esp?cies de leguminosas previamente selecionadas. Os experimentos foram conduzidos no campo experimental da AGRAER-MS, localizado em Campo Grande-MS, no per?odo de primavera-ver?o, no ano agr?cola 2005/06. O delineamento estat?stico utilizado foi o de blocos ao acaso, constitu?dos de dez tratamentos, sendo este compostos pelas esp?cies C. juncea, C. ochroleuca, C. mucronata, C. spectabilis, Mucuna cinza, Feij?o-bravo-do-cear? e Guandu fava larga; e como testemunhas as esp?cies Girassol, Milho e Braqui?ria. Por ocasi?o do florescimento de cada esp?cie de leguminosa e enchimento de gr?os das n?o-leguminosas, foram determinadas as produ??es de fitomassa a?rea. A partir das amostras de leguminosas e plantas testemunhas, estimaram-se as quantidades de N e a FBN, para tanto usando a t?cnica de dilui??o isot?pica de 15N . Posteriormente, conhecendo-se os valores de FBN, aplicou-se aos mesmos a equa??o utilizada na t?cnica de abund?ncia natural de 15N com a finalidade de estimar o valor B. Com rela??o ? produ??o de fitomassa a?rea, o Guandu fava larga obteve melhor desempenho seguido da C. ochroleuca, atingindo m?dias de 16,24 Mg ha -1 contra 14,44 Mg ha-1. Para a quantidade de nitrog?nio acumulada as esp?cies de leguminosas se comportaram de maneira semelhante, com destaque para o Guandu fava larga, C. ohcroleuca e C. Mucronata, atingido valores de 346,57 kg ha-1, 333,25 kg ha-1 e 277,35 kg ha-1 respectivamente. No tocante ? %FBN, observou-se que a t?cnica de dilui??o isot?pica de 15N n?o poderia ser aplicada para todas as esp?cies estudadas, uma vez que a maioria das esp?cies de leguminosas teve ciclo diferenciado das testemunhas, desta forma, as testemunhas n?o foram apropriadas, visto que a t?cnica exige que tanto as leguminosas como as testemunhas cres?am nas mesmas condi??es e de forma simult?nea. Contudo, para as variedades mais precoces que as testemunhas, o valor de FBN deve estar no m?nimo entre 73 a 87%. Somente na esp?cie C. Mucronata, foi poss?vel estimar a FBN e o valor B com o rigor que exigem as metodologias isot?picas aplicadas. O valor B para esta esp?cie foi de -3,69. Cap. IV O presente estudo teve o objetivo de avaliar o desempenho agron?mico do repolho em sistema plantio direto, sob manejo org?nico, e a contribui??o do pr?-cultivo de duas leguminosas de h?bitos de crescimento distintos em cons?rcio com milho, na forma??o de palhada. Ambos experimentos foram implantados no Campo Experimental da AGRAER, em Campo Grande-MS. O primeiro experimento consistiu no cons?rcio entre milho e C. juncea, sendo esta manejada, somente com ro?ada (taratamento 6), podada e posteriormente ro?ada (tratamento 5), al?m do cultivo do milho solteiro, C. juncea solteira, cultivo com preparo convencional do solo, com aus?ncia e presen?a de aduba??o, em quantidades equivalentes a 100 Kg N ha-1 no plantio e em cobertura 30 dias ap?s plantio do milho, perfazendo oito tratamentos com quatro repeti??es, dispostos em blocos ao acaso. Avaliaram-se as produ??es de mat?ria seca na parte a?rea das plantas de cobertura e da vegeta??o espont?nea. As caracter?sticas agron?micas avaliadas no repolho foram: produtividade, padr?o comercial, peso fresco e seco, al?m da fitomassa seca do pr?-cultivo. Neste experimento, verificaram-se melhores rendimentos quanto ao peso m?dio e di?metro da cabe?a quando se utilizaram C. juncea solteira, C.juncea ro?ada, milho com aduba??o de base e milho com aduba??o de base e cobertura, alcan?ando peso m?dio acima de 1,0 kg e di?metro das cabe?as acima de 10 cm. Quanto ? produtividade do milho e do repolho, estes n?o foram influenciados pelos diferentes tipos de cons?rcios, n?o havendo diferen?a estat?stica significativa entre os tratamentos, o que refletiu tamb?m na produ??o de mat?ria seca dos pr?-cultivos. No segundo experimento, o delineamento experimental utilizado foi o de blocos ao acaso com nove tratamentos e quatro repeti??es. Os tratamentos foram: o cons?rcio entre milho e mucuna cinza, sendo esta plantada em cinco ?pocas diferentes - ap?s a germina??o do milho, monocultivo do milho, monocultivo da mucuna, cultivo com preparo convencional do solo e pousio com vegeta??o espont?nea -, perfazendo um total de nove tratamentos. Os par?metros avaliados foram semelhantes aos do experimento anterior. A produ??o do repolho alcan?ou melhores rendimentos, 2,06 kg de peso m?dio da cabe?a; e, quando cultivado em sucess?o ao cons?rcio milho x M. Cinza, semeada aos 15 dias ap?s germina??o do milho, diferiu significativamente dos demais tratamentos. Ao se analisarem as produtividades do milho, notouse uma queda de rendimento em torno de 29% quando este foi consorciado com M. Cinza, aos 15 e 30 dias ap?s sua germina??o, ao comparar-lo aos demais pr?-cultivos utilizando-se cons?rcios