Celi Teixeira Feitosa

Comparação de quatro extratores de fósforo de solos

A comparative study of four methods used for the extraction of soil phosphorus, is presented. The methods were: a) IAC method, based on the extraction of, 5cm3 of soil with 50ml of 0.05N H2SO4; b) a modified Bray I method, based on the extraction of 2.5cm3 of soil with 50m1 of a solution 0.03N in NH4F and 0.025N in HCl; c) Olsens method, based on the extraction of 2.5cm3 of soil with 50ml of 0.5N NaHCO3 solution at pH 8.5; d) an anion exchange resin method based on the extraction of 5cm3 of soil with 2.5cm3 of an anion exchange resin contained in a polyester netting bag, by shaking in 50ml water. For each method, the correlation coefficients between soil phosphorus and the response to phosphorus fertilization of 16 field experiments of cotton and 16 field experiments of corn were, respectively, 0.683, 0.650, 0.391 and 0.802, indicating the superiority of the anion-exchange resin method for the assessment of soil phosphorus availability.

A análise de solo para discriminar respostas à adubação para a cultura do milho

In this paper some of the criteria that have been used in the State of Sao Paulo in soil test interpretation were studied, correlating soil test parameters with corn response to applied nitrogen, phosphorus or potassium in 25 field experiments. Exchangeable potassium and phosphorus soluble in 0.05N H2SO, correlated well with responses of the crop to the applied nutrients. Nitrogen responses could not be correlated to soil test values. Response curves and fertilizer efficiencies are presented for nitrogen, phosphorus and potassium. For the two last nutrients, the average curves are given for very low, low, medium and high soil test values.

Peanut growth and nutrient use evaluation

Avaliaram-se os padroes de crescimento e de absorcao de macro e de micronutrientes de quatro cultivares de amendoim, sendo tres de lancamento recente, IAC-Oira, lAC-Poitara e IAC-Tupa, todos de porte ereto e um mais antigo, Penapolis, de habito rasteiro. Os resultados obtidos mostraram que os cultivares recentes apresentaram o mesmo padrao de crescimento e de acumulo dos nutrientes e o cultivar a rasteiro, de ciclo mais longo, apresentou um padrao ligeiramente diferente. Dentre os cultivares estudados, IAC-Tupa e IAC-Oira apresentaram certa superioridade na eficiencia de aproveitamento da materia seca total produzida e do total de nutrientes translocados para a semente, orgao alvo da cultura do amendoim.

Efeito da adubação NPK na cultura da crotalária

No presente trabalho sao apresentados os resultados obtidos em oito experimentos em que se procurou determinar os efeitos de nitrogenio, fosforo e potassio, na producao de massa verde e sementes de Crotalaria juncea L. No estudo dos tres principais elementos, empregou-se um delineamento fatorial 3a com duas repeticoes. Foram estudadas as dosagens de 0, 30 e 60 de N; 0, 60 e 120 de P2O5 e 0, 30 e 60 de K2O, em quilograma/hectare, empregados sob a forma de salitre-do-chile, superfosfato simples e cloreto de potassio respectivamente. Os experimentos foram realizados nos anos agricolas 1967/68 e 1968/69, nas Estacoes Experimentais de Campinas, Tiete, Tatui e Ribeirao Preto e, segundo a Comissao de Solos do Ministerio da Agricultura, respectivamente, em solo: Latassolo roxo, serie Chapadao; Podzolico vermelho-amarelo variacao Piracicaba; Latossolo roxo e Latossolo roxo. Os resultados mostram que, na maioria dos experimentos, o emprego do fosforo aumentou significativamente a producao de massa verde e sementes. O nitrogenio apresentou efeito significativo em alguns deles, ao passo que o efeito do potassio foi praticamente nulo, so apresentando significância quando em presenca do fosforo ou do fosforo e nitrogenio juntos.

Omissão de macronutrientes em rami

Ramie plants (Boehmeria nivea Gaud.) were cultivated in rinsed sand, under greenhouse conditions, in pots irrigated with destilled water, complete nutrient solution and nutrient solutions with absence of one macronutrient each time (N, P, K, Ca, Mg and S). After three months, the plants showed typical symptoms of deficiency associated to low content of each nutrient in the leaves and plant growth reduction.

Efeito de diferentes fertilizantes fosfatados, em diversas condições de acidez do solo, na produção do trigo em vasos

Em casa de vegetacao conduziu-se um experimento com trigo, em vasos com Latossolo Vermelho Escuro orto, proveniente do municipio de Itapetininga, com o objetivo de verificar o comportamento de diversos adubos fosfatados, sob tres condicoes de acidez do solo. Foram estudadas as adicoes de 0, 100 e 200 kg/ha de P205, em presenca e em ausencia de calcario. Os fertilizantes usados foram superfosfatos simples e tripo, termofosfato, fosfato de diamonio e apatita-de-araxa, sempre em presenca de nitrogenio e potassio. Os resultados mostraram efeito significativo para doses de calcario, tanto para peso seco de plantas como para peso seco de graos. Entre os fertilizantes, o superfosfato simples e o termofosfato foram os que melhor se comportaram para peso de graos. A seguir vem o fosfato de diamonio e o superfosfato triplo, que nao diferiram entre si, porem comportaram-se estatisticamente diferentes da apatita-de-araxa, tanto para peso seco de plantas como para graos. Com a aplicacao de calcario ao solo, para correcao da acidez, todos os fosfatos soluveis apresentaram, igualmente, muito boa resposta na producao da planta, diferindo do fosfato tricalcico, que mostrou pequeno efeito.

ADUBAÇÃO DO AMENDOIM (Arachis hypogaea L.) EM ÁREA DE REFORMA DE CANAVIAL

Six field experiments were carried out during four growing seasons (86/87; 87/88; 88/89; 89/90) in order to study the availability of the residual fertilization effect of the sugar cane crop on the peanut crop. The treatments consisted of applications of 0, 30, 60, and 90Kg/ha of P2O5 as triple superphosphate and 0 and 30Kg/ha of K2O as potassium chloride, arranged in a randomized complete block design. The seeds were innoculated with selected Bradyrhizobium bacteria (SMS-729, SMS-400, SMS-438) as source of nitrogen. The soils were not limed. Fertilizer effect was observed in a sandy and a clayey soil, of Artur Nogueira-SP, Brazil and Campinas-SP, Brazil, respectively. No fertilizing effect in peanut production was observed for the other locations. It can be concluded that the fertilizer applied to sugar cane was sufficient to furnish the nutrients necessary for the peanut crop, even at the medium and low soil fertility conditions.

ADUBAÇÃO VERDE E ORGÂNICA PARA O CULTIVO DO AMENDOIM (Arachis hypogaea L)

During the 1986/94 growing seasons, experiments were carried out on a Red-Dark Podzolic soil at the Experimental Station of Monte Alegre do Sul-SP, Brazil, in order to verify the continuous and noncontinuous peanut planting, the incorporation of green manure, of chicken manure and leaving the soil fallow, on the spring productivity of peanut crop. The use of incorporated Mucuna aterrima, as green manure, in rotation with peanut, increased the percentual yield by 64% of the continuous peanut planting; two annual cropping systems of peanut can not be grown, because reduce yields. Incorporation of Mucuna aterrima as green manure, chicken manure and fallow increased the concentration of the phosphorus in the soil, when compared to the continuous planting of peanut crop.

Omissão de macronutrientes em junco

Rush plants (Cyperus malaccensis Lam.) were cultivated in sand culture under greenhouse conditions, irrigated with a complet nutrient solution, nutrient solutions with absence of each macronutrient and distilled water. Symptoms of macronutrient deficiencies were observed, except for calcium and magnesium and were related to the contents of the elements in the plant.

Adubação NPK e calagem na produção de massa verde e sementes de crotalária

Two field experiments were conducted in order to evaluate the effect of N, P, K fertilization, with and without liming, on the total green matter and seed production of sunn hemp (Crotalaria juncea L.). The experiments were done in the experimental stations of the Instituto Agronomico of State of Sao Paulo, Brazil, located in Campinas and Tatui, during the years of 1969/1970, in soils of the group Latosol >. The results obtained indicated a positive effect of P fertilization on the sunn hemp yield, in the soils that presented less soil P content. Significant increases in yield were obtained with the application of dolomitic lime, specially in the experimental station of Tatui.