Subjects: Biology >> Ecology submitted time 2017-11-29 Cooperative journals: 《中国生态农业学报》
Abstract： To achieve the optimum tillage depth of 22cm and soil bulk density of 1.1~1.3 g譪m-3 of topsoil layer for maize production, and solve the farmland soil structure issue of shallow topsoil layer (16cm), hard (bulk density 1.55~1.62 g譪m-3) and thick (45 cm) plow pan in Inner Mongolia Plain irrigation. The study was conducted on the four-year location experiment of deep tillage maize straw manure after harvest, the annual average maize straw returned to soil was 20�34.79 kg議m-2 and four experiment treatments (SF1-SF4) of deep tillage maize straw manure from one to four years and a control group (CK) of non-deepening straw were formed year by year. Result 1, it showed that in 0-40 cm layer soil, the average value of bulk density (SF1-SF4) was significantly reduced by 11.38%, 12.28%, 15.30% and 15.50% compared with CK, and the average value of soil compaction (SF1-SF4) was significantly decreased by 1�36 kPa, 1�63 kPa, 1�36 kPa and 1�55 kPa compared with CK. Result 2, it showed that in 0-20 cm layer, SF4 of more than 0.25mm aggregate content and geometric mean diameter was significantly reduced by 13.79% and 27.21% compared with CK; SF3 and SF4 of the mean weight diameter of aggregates was reduced by 8.25% and 19.59% compared with CK; SF1 of the damage rate of soil aggregates was significantly decreased by 9.56% compared with CK; SF1 of the sabotage water-stable aggregates was reduced by 9.56% compared with CK, SF4 of the fractal dimension of aggregates was significantly increased by 7.30% compared with CK. Result 3, it showed that in 20~40 cm layer, SF1 and SF2 of more than 0.25 mm aggregate content was significantly increased by 13.69% and 17.83% compared with CK; SF2 of the mean weight diameter and geometric mean diameter of aggregates was significantly increased by 23.92% and 53.38% compared with CK; SF1~SF4 of the damage rate of soil aggregates was significantly decreased by 9.20%, 3.02%, 8.38% and 3.16% compared with CK; SF1-SF4 of the sabotage water-stable aggregates was significantly increased by 13.58%, 16.49%, 22.67% and 25.42% compared with CK, SF2 of the fractal dimension of aggregates was significantly decreased by 7.39% compared with CK. Result 4, it showed that SF1~SF4 of the soil organic matter was significantly increased by 16.32%, 24.78%, 25.07% and 25.56% compared with CK; SF1-SF4 of the available nitrogen was significantly increased by 16.86%, 14.46%, 17.20% and 21.95% compared with CK; SF1~SF4 of the available phosphorus was significantly increased by 6.8%, 12.07%, 17.85% and 23.30% compared with CK; SF1~SF4 of the available potassium was significantly increased by 17.59%, 16.34%, 20.49% and 29.85% compared with CK; SF3 and SF4 of the soil pH was significantly decreased by 1.95% and 1.73%. There was a significant effect of deep tillage maize straw manure from one to four years on the soil structure of 0-40 cm soil layer. 2-year deep tillage maize straw manure was most suitable for improving the structure of soil plow pan; 3-year and 4-year deep tillage maize straw manure were most suitable for improving the structure of topsoil layer. In the application of deep tillage maize straw manure, it should be noted that the depth of plowing was 40cm, which should be reduced by 30 cm two years later. The reason was that the damage rate of soil aggregates of plow pan and the sabotage water-stable aggregatess were increased by the continuous 40cm deepening and the damage of soil plow pan structure was aggravated; the depth of plowing was reduced by 20cm, which maintained deep tillage maize straw manure on topsoil layer, the decomposition of straw and soil organic matter were increased, the damage rate of soil aggregates was decreased, and the sabotage water-stable aggregatess was decreased, which was conducive to cultivating topsoil layer.
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