水氮管理对麦后复播大豆土壤固碳效应和产量的影响

Effects of water and nitrogen management on soil carbon sequestration and soybean yields in wheat-soybean cropping fields

为探求伊犁河谷地区复播大豆高产低碳的水氮管理组合,为建立高产固碳农业技术提供一定理论依据,2012—2014年于伊宁县开展了不同水氮管理对复播大豆土壤总有机碳、碳库管理指数及产量影响的田间试验。采用水、氮二因素裂区试验设计,设置4个灌水量处理:3000(W1)、3600(W2)、4200(W3)、4800(W4)m^3·hm^(-2);设置3个施氮量处理:0(N0)、150(N1)、300(N2)kg·hm^(-2)。结果表明,随着施氮量或灌水量的增加,土壤有机碳、活性有机碳和非活性有机碳含量均呈现"先增后降"的趋势,且均在W3N1组合处理下达到最大,且其碳库管理指数和产量均达到最大。大豆产量与土壤有机碳、活性有机碳、碳库管理指数均存在正相关关系,且与活性有机碳的相关系数最大,达0.898,说明W3N1组合处理不仅更有利于土壤有机碳的固定,而且有利于复播大豆产量的提高。

A field experiment was conducted to study the effects of different water and nitrogen management on soil organic carbon, carbon pool management index, and soybean yields in the wheat-soybean fields in Yining County from 2012 to 2014. Experimental design was water and nitrogen two factor split-plot design, with 4 irrigation levels, namely 3000（W1）, 3600（W2）, 4200（W3）, and 4800（W4）m^3·hm^-2,and 3 nitrogen levels： 0（N0）, 150（N1）, and 300（N2）kg·hm^-2. Results showed that content of soil organic carbon and non-active organic carbon decreased with increasing soil depth. As nitrogen rates or irrigation water amount increased, soil organic carbon, organic carbon active and non-active organic carbon content showed ＂initial increase and then decrease＂ pattern, with the highest found at W3N1 combination treatment. Soybean yield was positively correlated with soil organic carbon, active organic carbon and carbon pool management index,with the greatest correlation coefficient found in active organic carbon. Our results suggest that the W3N1 combination would not only enhance soil organic carbon sequestration and reduce emissions, but could also improve soil fertility and increase soybean production.