Wheat Straw Decomposition in the Field

Abstract

Wheat (Triticum aestivum) varieties ‘Nugaines’ and ‘Lemhi’ were grown on Portneuf silt loam soil with three nitrogen and three irrigation treatments in 1967. After harvest, 84 kg N/ha was applied to half of each plot before plowing. Uniform straw samples were enclosed in fiberglass cloth bags and buried in the plots September 7. The straw placed in N‐treated plots received sufficient N in solution to increase the straw N from about 0.29 to 1.5%. Straw samples were recovered November 15, after the soil had cooled below 4C, and at three later sampling dates to October 3, 1968, after a bean crop (Phaseolus spp.) was harvested. Weight loss and total N were determined on all samplings and total C on the first sampling. Decomposition was greater with N than without it for the November sampling and the March sampling for Nugaines but not at other samplings for both varieties. The weight of N in both N‐treated straw varieties decreased 55% by November 15, while in the non‐N‐treated Nugaines and Lemhi straw, N weight increased 12 and 32%, respectively, by March 22. Later, N moved out of all the straw samples when the N percentages were much lower than the theoretical equilibrium value.

Mineralização da palhada e crescimento de raízes de cana-de-açúcar relacionados com a adubação nitrogenada de plantio

“…Como a palhada de cana-de-açúcar apresenta, em média, uma relação C:N de aproximadamente 100, é de se esperar grande imobilização do N do solo, uma vez que, como regra geral, para relações C:N maiores que 15 a 20, ocorre imobilização (Smith & Douglas, 1971;Siqueira & Franco, 1988).…”

Decomposition of rice residue in tropical soils

“…2). SMITH and DOUGLAS (5) reported that loss in weight of wheat straw in the field was larger at the early stage but smaller at the later stage when fertilizer was added than when it was not. Kuo and BARTHOLOMEW (3) reported that the addition of inorganic nitrogen (ammonium sulfate and urea) to corn stalks both accelerated and retarded decomposition-large additions of inorganic nitrogen retarded loss in weight of corn stalks.…”

Decomposição do resíduo de milho e variáveis relacionadas

“…A decomposição dos resíduos culturais depende da natureza e da quantidade do material vegetal (Brown & Dickey, 1970;Bertol et al, 1998;Gilmour et al, 1998), da fertilidade do solo (Smith & Douglas, 1968, 1971, do manejo da cobertura e do grau de fracionamento do resíduo (House & Stinner, 1987), além de condições climáticas (Lyon, 1998;Gilmour et al, 1998), representadas principalmente pelo regime de chuvas e pela temperatura, que influem na atividade microbiana do solo.…”

“…A velocidade de decomposição, segundo Smith & Douglas (1968;1971), não é influenciada, por outro lado, pela quantidade de N mineral do solo.…”