| In order to explore the effect of soil conservation and soil moisture conservation on soil cultivation and straw mulching in the autumn and dry land of Sichuan hilly land and the effect on Winter Wheat Yield and water and fertilizer utilization,the experiment was carried out in 2015-2017 years in Zhujia village,Sichuan,Renshou County.In the experiment,two factors were used in the split plot design.Under no tillage,rotary tillage,tillage and ploughing,the corn straw mulching and non mulching were set up.The effects of cultivation methods and straw mulching on soil physical and chemical properties,upper ground and underground growth were studied.The main experimental results were as follows:1.Tillage and straw mulching significantly affected soil water content.2015/2016,in terms of soil tillage layer(0-20cm),the soil moisture content of the tillering stage was the highest in the tillering stage,the highest in the jointing period,the highest in the booting period,and the difference in the water content of the 20-100 cm soil layer under the various tillage methods in each period,and the drought year type(2016/2017)and different tillage.There is no significant difference in soil water content between the methods.The two annual straw mulching was beneficial to the increase of soil water content.The effect of water conservation of the straw mulching on the drought year was sustainable before the wheat flowering,and the soil moisture content in the 0~40 cm soil layer was significantly higher than that of the non cover treatment,and the moisture conservation effect of the wet year straw mulching was sustainable to the jointing period.2.Tillage and straw mulching significantly affected soil temperature.The soil temperature in the afternoon was the highest in the afternoon,in turn,tillage > pine tillage > rotary tillage > no tillage;dry year,low temperature in the afternoon,the highest in no tillage,followed by no tillage > pine tillage > rotary tillage > tilling.The variation coefficient of temperature from morning to afternoon is larger than that of rotary tillage and tillage,and the coefficient of variation of no tillage and loosening is small.After straw mulching,the temperature decreased slightly,but the coefficient of variation of ground temperature decreased.3.Tillage and straw mulching affected soil enzyme activity,phosphatase activity and soil nitrogen nutrition and phosphorus.The effect of tillage method on soil enzyme activity was not steady,the content of NH4+-N and available phosphorus in the corresponding soil layer was not significant,but the activity of urease and phosphatase was significantly increased after straw mulching,and the activity of enzyme in tillering,jointing,flowering and mature was higher than that of non cover treatment.The content of NH4+-N and available phosphorus in the corresponding soil layer was significantly higher than that of no overlay.Cover treatment.4.Tillage treatment was beneficial to increase root activity during tillering stage,but there was no significant difference between treatments.Root activity decreased after straw mulching and significant difference in tillering stage.The root length,total surface area,average diameter,total root volume and root tip number of the tillering stage were increased after rotary tillage treatment.The morphological parameters of wheat root decreased significantly at the tillering stage under straw mulching,and there was no significant difference between the jointing stage and the non mulching period.5.Straw mulching has a greater impact on population quality than tillage.No tillage was beneficial to the tillering and heading of wheat in upland and dry land,but there was no significant difference in LAI between tillering,jointing and flowering stage among different tillage methods.The total difference of dry matter accumulation in tillering stage,jointing stage,booting stage,flowering stage and maturing stage was not significant,and straw mulching promoted tillering and tillering,tillering and jointing periods.In the flowering stage,LAI increased significantly,and dry matter accumulation in each stage increased significantly,and dry matter accumulation after anthesis increased.6.In two years,the yield of rotary tillage was higher,and the yield increased by 14%,6.6% and 8% respectively than that of rotary tillage,tillage and pine tillage in drought years.The increase of yield was due to the increase of effective spikes and spikes,and there was no significant difference between the wet year and the rotary tillage and the tillage,and the difference was significant with the pine tillage.After straw mulching,the yield was promoted significantly in the drought year type,and the yield after covering was 2 times that of the non cover,mainly due to the significant increase of the effective spikes and spikes,and the increase of 42.4% and 21.1% of the effective panicle and ear grain number,respectively,while the yield effect of the wet year straw mulching was not significant.7.Rotary tillage and straw mulching are beneficial to improve the efficiency of water and fertilizer utilization.The synergistic effect of straw mulching is greater in drought years.The water use efficiency of straw mulching in drought years is 86.9%,and the partial productivity of nitrogen fertilizer is 2 times that of no cover.To sum up,rotary tillage can promote the increase of water content in the tillering stage,optimize the tillering period and increase the number of effective spikes and spikes,and increase the yield of the effective spikes and spikes.The effect of straw mulching on water preservation can be sustained before flowering,and can buffer low temperature fluctuation,promote the activity of soil enzyme and increase the content of ammonium nitrogen and available phosphorus in the soil of the tilth layer,and cover the population LAI after covering.The amount of dry matter accumulation is high,and the dry matter accumulation after anthesis is large.The study indicates that rotary tillage + straw mulching in autumn autumn season is a green technology way for high yield and high efficiency utilization of wheat in Hilly and dry land of Sichuan. |
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