Experiment On The Conservation Tillage Of Corn And The Dynamic Simulation Of Water Transport In SPAC

Compared with the traditional cultivation, the mulch tillage is a new cultivationtechnology which by reduced tillage or no-tillage to mulch the surface with the crop strawand stubble to reduce the soil water and the wind erosion improving the soil fertility anddrought resistant ability. Due to the big differences among the geography and climaticfeatures and the economic level in different region, the applicable scale and methods of themulch tillage are affected. So as mulch tillage technology can be further promotion andapplication. It is necessary to study the storage and preservation of soil moisture and theproduction mechanism.Aim at the current situation of agricultural water shortage in the dry area in the northeast,the mulch tillage technology’s theory and its application were studied in the region combinedwith the youth science fund project of national science foundation of china (51109037)“Study of the mechanism of different mulching tillage measures on soil regulation andmoisture conservation and the forecast system of soil moisture in the black soil area in theSongnen plain”.Field experiments results showed that the calescence effect is obvious in the maizeseedling stage under the treatment of crushed stalk and compaction. The seedling emergencewas affected by every treatment to some extent. LAI were all higher than the conventionaltillage in the middle and later period of the jointing, and the plant height and the stemdiameter also had the same rule. Maize yield was shown that the shallow-tillage mulchtreatment was the best and improved obviously, and the complete mulchage of no-till was theworst. The soil water use efficiency of the shallow-tillage mulch treatment was the highestand the complete coverage of no-till was lower than the conventional tillage. The soilmoisture content were improved1.94%-32.45%by mulch treatment than the traditionaltillage in seeding time and growth period and had obvious effect to improve the surface soilmoisture and had little effect to the deep. Each treatment was beneficial to the increase ofsoil organic matter content and to accelerate the decomposition of the organic matter, andensure the supply of crop nutrients. Proper shallow-tillage can improve the soil permeabilityand activate aged humus and promote the rainfall infiltration and the release and utilizationof available nutrient. The adjustment ability of crushed stalk mulching treatment on soil PHneeds further study. The rest of treatments all can make the PH from6.5to7which aresuitable for maize growth. Summing up the above, shallow-tillage mulch and compaction treatment can regulate ground temperature effectively and hold water effectively under thisexperimental condition. Under this treatment, the utilization rate of soil moisture could behigher and the yield could be increased with the interaction of soil nutrient content andtopsoil moisture. In a word, the shallow-tillage mulch and compaction treatment was a goodway of crop straw comprehensive utilization and was the best tillage method in this study andwas suitable in the northern area.Two-dimensional soil water movement models under the conditions of completecoverage of no-till and compaction treatment, shallow-tillage mulch and compactiontreatment, stubble mulch and strip mulch were built by researching the soil profile water andthe water retention mechanism under different mulching measures and studying the mode ofwater saving and production increasing of the corn. They were solved by the ADI method andwere suitable to forecast the soil moisture content. The field soil moisture dynamic changeprocess was reappeared by the numerical simulation of the process of rainfall infiltration onsoil. The results showed that the significant changes in soil moisture area mainlyconcentrated in the depth of0to40cm and revealed the soil water movement laws underdifferent mulching treatment.The research achievements can provide the theoretical basis for the promotion andapplication of mulch tillage technology in the northeast. Two-dimensional soil watermovement models under the farming mode of complete coverage of no-till and compactiontreatment, shallow-tillage mulch and compaction treatment, stubble mulch, strip mulch werebuilt for analyzing the field soil moisture dynamic change process. The mulch tillagemeasure which’s suitable in the northeast were put forward based on the field experiment andtheoretical analysis.