Effect of soil treatment with cereal straw and method of crop establishment on field pea (Pisum sativum L.) N2 fixation

Autor: J. Evans, G. E. O'Connor, D. J. Carpenter, NA Fettell, Phillip M. Chalk
Rok vydání: 1997
Předmět:
Zdroj: Biology and Fertility of Soils. 24:87-95
ISSN: 1432-0789
0178-2762
DOI: 10.1007/bf01420226
Popis: The effects of soil incorporation with cereal straw (nil, 2.5, 5 and 10 t straw ha−1) and direct drilling on the proportion and amount of pea N derived from biological N fixation were investigated in three field experiments. Fixed N was determined by15N dilution using barley as a reference plant. The three sites were on acidic, red clay-loams in the cropping zone of southeastern Australia. Seasonal plant available soil N, as determined by the N accumulated in barley, was 31, 56 and 158 kg N ha−1, for the three sites. Incorporated straw reduced soil nitrate at sowing by 10–50 kg N ha−1 (0–30 cm), and 5 or 10 t straw ha−1 reduced barley uptake of N by 10–38 kg N ha−1. However, reducing plant available soil N was generally ineffective for increasing the N fixed by pea. Fixed N increased only at the site with the least plant-available N, and only one-third of the increase could be attributed to lower soil N uptake by pea. There was no evidence that direct drilling pea increased fixed N by decreasing crop uptake of soil N. It is proposed that a lower requirement for soil N by pea as compared to barley, and availability of mineral N beneath the soil layer treated with straw, minimise the effectiveness of straw incorporation for increasing the N fixed by pea.
Databáze: OpenAIRE
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