【摘要】 为了提高改土效率,打破白浆土障碍层次白浆层,改善贫瘠的心土层创造有利条件,该文设计了将白浆土"上翻20 cm,下混30 cm,同时间隔62 cm不混拌"的心土间隔混层犁。2016-2017年在黑龙江省八五四农场设置心土间隔混层区和浅翻深松区大区对比试验,研究改土作业后土壤理化性质、大豆产量及其农艺性状变化,明确改土机械作业效果与作物增产机理。结果表明:与浅翻深松相比,心土间隔处理改土2 a内:改善白浆土心土层土壤物理性质,提高土壤含水率,>20～40 cm土层土壤含水率提高幅度为2.13～3.20个百分点;降低心土层土壤硬度,硬度值降低40%～50%,且在>20～40cm心土层没有出现峰值,改善土壤三相比例,固相值降低5.06个百分点,液相值增加3.17个百分点,气相值增加1.89个百分点。改善心土层化学性质,>20～40 cm土层碱解氮提高33.77%,有效磷提高39.25%,速效钾提高4.16%,有机质提高15.85%,同时提高心土层全量养分含量,降低土壤pH值,但效果不明显。连续调查两年大豆产量,心土间隔混层区比浅翻深松区增产12.66%～13.28%,一次改土后效时间长,增产效果显著。该研究结果可为旱地白浆土及其同类低产土壤的改良提供技术支撑。更多还原

【Abstract】 Planosol is one of the main agricultural soils in the northeast of China, concentrates in Heilongjiang and Jilin provinces relatively. Its total area is approximately 3.312 million hm2 in Heilongjiang Province, centrally distributed in the Sanjiang Plain, its cultivated land area is about 0.88 million hm2, accounting for 25.4% of the total arable land in the area. The subsoil of planosol often presents the physical and chemical characteristics of "hard, board and thin" during the growing period of crops, which results in serious drought and water logging. According to the characteristics of the two-layer nature of the planosol in its mechanical composition, we proposed a new soil modification route to treat the "sand" of the Aw(planosol layer) horizon with the "clay" of the B horizon(illuvia horizon), clarified the principle of "the Ap horizon in depth of 20 cm undisturbed, while mix the subsoil in depth of 30-40 cm", and developed a three-stage subsoil mixing plough which could mixed the Aw horizon and the horizon with the ratio of 1:1 under the condition of the black soil layer position unchanged, improved the permeability and the water storage capability of the subsoil. After many years experiment and demonstration, the whole subsoil layer mixed, seriously affect the mechanical seeding. In order to improve the soil modification efficiency, form suitable soil structure and improve barren subsoil, the subsoil interval mixing plough was designed on the basis of the three-stage subsoil mixing plough, which could plough the Ap horizon in depth of 20 cm undisturbed, mix the subsoil in depth of 30 cm below, separate 62 cm without mixing. We conducted field experiment in the 854 state farm during 2016-2017, and investigated the physical and chemical characteristics of soil and the agronomic traits and yield of soybean of subsoil interval mixing area and surface ploughing and deep digging area to definite the yield-increasing mechanism of the interval subsoil mixing plough The result showed that compared with surface ploughing and deep digging area two years after soil modification, the subsoil interval mixing area improved the physical characteristics of the subsoil, during 20-40 cm soil layer, the soil water content increased by 2.13-3.20 percentage point, the hardness reduced by 40%-50%,and there was no peak; improved the soil permeability, the solid phase decreased by 5.06 percentage point, the liquid phase increased by 3.17 percentage point, and the gas phase increased by 1.89 percentage point; improved nutrient content of subsoil, the available nitrogen increased by 33.77%, the available phosphorus increased by 39.25%, the available potassium increased by 4.16% and the organic matter increased by15.85%, improved the total nutrients content of subsoil and alleviated soil acidity meanwhile. The yield of soybean in two years increased by 12.66%-13.28% compared with the CK area, the soil modification effect last long at a time, significant increase in production. The results could provide technical support for improving planosol and the same low yield soil and promoting high crop yields.更多还原