Effects Of Tillage Measure On The Population Of Mechanical Sowing Wheat And Soil Moisture-conserving,& Evaluate Its Application Effect With Comprehensive Evaluation, In Sichuan Hilly Areas

In order to explore the agricultural measures that can improve the application effect of wheat mechanical sowing technology in hilly dryland region, a field experiment was carried out in Sichuan Province from November 2011 to August 2013. The main-plots was for three tillage methods (no-tillage, rotary tillage and conventional tillage) and the sup-plot was for straw-mulching (no straw-mulching was CK). Trough this experiment to research the effects of tillage measures on mechanical sowing quality, population quality and yield of mechanical sowing wheat, then analyze the effects of tillage measures on soil moisture-conserving during wheat growth stage, and use comprehensive evaluation to evaluate the effect of different tillage measures applied to the wheat mechanical sowing technology. The main results showed as follows:1. Tillage measures had significant effect on mechanical sowing quality. Tests showed that the soil preparation quality and seed-covering quality were better under rotary tillage and conventional tillage, the seed-airing rate and the seedling less ridges rate were lower, and seeding uniformity. The seed-covering quality was not good, the seed-airing rate, the seedling less ridges rate and rate of emergence were higher, under no-tillage. Straw-mulching could promote the rate of field emergence of wheat mechanical sowing, its rate of field emergence was 5% more than no straw-mulching. But field observations indicated that straw-mulching would delay wheat sprouting and wheat seedlings were weak. Those indicated that the mechanical sowing quality was better under rotary tillage, conventional tillage and straw-mulching.2. Population quality of wheat was strongly affected by tillage measures. Wheat population quality was improved under no-tillage and rotary tillage treatment, compared with that of conventional tillage treatment, and the largest positive effect was detected in no-tillage treatment. And straw-mulching was advantageous to wheat population quality in all three tillage treatments. The results showed that the greatest tillering rate of wheat was found in no-tillage treatment, and the tillering rate was significantly enhanced by straw-mulching at peak tillering stage. Tillering ability of wheat increased in no tillage and rotary tillage by 60.5% and 22.4%, compared with conventional tillage treatment. Tillering ability and spikelet number per plant were raised in straw-mulching treatment by 36.6% and 19.2%. Leaf area index (LAI) in population under no-tillage treatment was higher than others, and enhanced by straw-mulching. The major difference in root growth among tillage treatments was vertical distribution of root in the soil, more of root grown in shallow layer soil under no-tillage and rotary tillage treatments than conventional tillage. And in straw-mulching treatment, root biomass of wheat was increased, and a larger portion of root was found in shallow layer soil. Biomass accumulation of wheat population was augmented in no tillage treatment compared with rotary tillage and conventional tillage, and enhanced by straw mulching. Compared with conventional tillage treatment, post-anthesis biomass increased in no-tillage and rotary tillage by 8.1% and 4.0%. Post-anthesis biomass was raised in straw-mulching treatment by 31.6%.3. Tillage measures had significant influence on the wheat yield. The numbers of effective spikes under no-tillage were higher than those under rotary tillage, while those under conventional tillage were the lowest; tillage measure had no significant effect on the number of grains per spike and 1000-grain weight, however, the wheat yield under no-tillage and rotary tillage were 12.6% and 3.9% higher than that under conventional tillage, respectively. The numbers of effective spikes under straw-mulching were significantly higher than those under no straw-mulching. In general, compared to no straw-mulching, the numbers of grains per spikes under straw mulching were increased by 5.2; the wheat yield under straw-mulching were significantly increased by 17.3%; the 1000-grain weight was decreased, moreover, there was on significantly difference between straw-mulching and no straw-mulching on the 1000-grain weight. The results showed that the wheat yield of no-tillage with straw-mulching were the highest, while those under conventional tillage with on straw mulching were the lowest. The no-tillage and rotary tillage had a number of effective spikes were the basis for increasing the wheat yield. However, the numbers of effective spikes were significantly increased by the straw mulching, and the numbers of grains per spike were increased by seed-setting rate under straw-mulching, and it was investigated on effects of straw-mulching on wheat yield.4. There were significant impacts of tillage measures on soil moisture-conserving. Compared to no-tillage, the ability to soil moisture-conserving was weak under rotary tillage and conventional tillage, and there was a significant difference in wheat early stage. The difference of ability to soil moisture-conserving among tillage measures reduced with the shallow layer soil gradually compacted and the advance in growing period. Straw-mulching could promote the soil moisture-conserving, especially for shallow layer soil (0～40 cm), this effect run through the whole growth period. Although the ability to soil moisture-conserving of straw-mulching gradually reduced with the shallow layer soil gradually compacted and the advance in growing period, but it also had some effect on soil moisture-conserving.5. The analysis of comprehensive evaluation showed that the major difference in energy and materials input of tillage methods were in what the soil preparation, and more energy and materials input was needed under conventional tillage. When it comes to the mechanical sowing quality, population quality, yield and soil moisture-conserving, no-tillage and rotary tillage were perform much better than conventional tillage, and no-tillage was perform best. Compared to no straw-mulching, Straw-mulching had an obvious promotion effect on the application of wheat mechanical sowing technology. All this suggested that compared to conventional tillage and no straw-mulching, no-tillage, rotary tillage and straw-mulching could promote the application of wheat mechanical sowing technology.In conclusion, there was good mechanical sowing quality under conventional tillage and rotary tillage, and in order to adapt to the no-tillage, the performance of planter needed to be perfected. No-tillage and straw-mulching had an obvious promotion effect on the rate of field emergence of mechanical sowing wheat. No-tillage and rotary tillage could promote the tillers, effective spikes and dry matter accumulation, and had an obvious effect in increasing production. Straw-mulching had significant influence on population quality and soil moisture-conserving, could increase yield. The analysis of comprehensive evaluation showed that compared to conventional tillage and no straw-mulching, no-tillage, rotary tillage and straw-mulching could promote the application of wheat mechanical sowing technology. The combination of no-tillage, rotary tillage and straw-mulching had an promotion effect on application of wheat mechanical sowing technology, so it was the suitable agricultural measures that could adapt to the wheat mechanical sowing technology, in Sichuan Province hilly dryland area.