河西绿洲灌区间作绿肥及其不同利用方式对玉米产量及土壤肥力的提升效应

目的]研究玉米间作不同绿肥及绿肥不同利用方式在河西绿洲灌区的生产效益.方法]田间定位试验始于2009年,该试验为河西绿洲灌区的典型种植模式,至取样时试验已进行12年.与玉米间作的绿肥作物包括针叶豌豆、甜豌豆、草木樨,每种绿肥均采用压青与根茬还田两种方式,以玉米单作为对照(CK).测定了玉米和绿肥生物量、产量构成因素...

Intercropping maize with green manure crops at various utilization patterns improvess maize yield and soil fertility in Hexi Oasis irrigated area

  【Objectives】  The effects of intercropping green manures on maize yield and soil fertility were compared, to provide reference for efficient maize production in Hexi Oasis irrigation area.  【Methods】  The 12-year old experiment was established in 2009 and the intercropped green manure crops were melilotus, needle leaf pea, and sweet pea, and each crop was returned to the field in two patterns, incorporating whole fresh plants or just stubbles. Mono maize cropping was used as control (CK). The yield, yield components, and nutrient accumulation of maize and green manure were analyzed, the soil samples were collected at the same time for the determination of fertility and enzyme activities.   【Results】  The incorporation of whole plants and stubble of melilotus, whole plants of needle leaf pea and sweet pea significantly increased maize yield by 28.06%, 16.74%, 13.99%, and 9.86%, compared with CK, the incorporation of only stubbles of needle leaf pea and sweet pea did affect yield in 2020. Incorporating the whole fresh melilotus plants significantly increased maize plant height, ear diameter, ear length, kernel number, and aboveground weight, thus, led to high grain yield, and the lowest difference of annual maize yield variation coefficient. Compared with CK, incorporating whole plant of fresh needle leaf pea and sweet pea significantly increased soil inorganic N and available K concentrations by 15.39%–22.48% and 9.61%–15.92%, respectively. Incorporating needle leaf pea elicited the highest soil total N concentrations and maize N accumulations, which were 12.7% and 76.89% higher than that of CK. Intercropping needle leaf pea and sweet pea improved the soil alkaline phosphatase activity by 13.46%–45.03%, meanwhile incorporating sweet pea enhanced urease activity by 19.75%. The aggregated boosted tree (ABT) analysis indicted that soil total N, available K and urease activity were the top three contributors to maize yield, accounting for 41.08%, 10.15%, and 12.24%, respectively.   【Conclusions】  In the maize-green manure intercropping system, incorporating whole plants or just stubbles of melilotus are efficient in increasing maize yield, while incorporating whole fresh plant is better than just returning stubbles. Incorporating the whole plants of either needle leaf pea or sweet pea could significantly improve maize yield, but they are more efficient in improving soil fertility.