Effect Of Plowing Depth And Straw Returned On Soil Properties And Crop Growth

It is of significance to very important to promote the crop growth by combining straw turnover with tillage measures to improve soil physical and chemical properties against the problems of soil hardening,topsoil shallow and loss of soil and water,etc.caused by modern agriculture production.Typical red soil sloping lands in Yunnan have been focused on the paper to study the improvement effect and influence of straw(wheat and cornstalk)turnover and tillage measures(no tillage,aggressive turnover,shallow turnover and rotary tillage)on the soil physical and chemical properties of the surface and on the "wheat-corn|| pepper" crop growing,respectively.In addition,a survey research has also been done for the promoting status and effectiveness of agriculture in Yanshan County.Main results and conclusions are presented as follows:1.Straw turnover and tillage measures have had great influences on the soil physical characteristics,especially for the deep soil.Specifically,comparing with no tillage,turnover could significantly reduce the soil bulk density yet with no obvious difference among different depths of tillage.The straw turnover could ease the soil bulk density increasing with the growth sage of push soils;Rotary tillage,turnover and straw turnover could also reduce the soil density.Density of the surface soils processed by aggressive turnover that was 22.39% lower than that without tillage.The straw turnover reduced anti-shearing force of the soil,specially the deep soil.Soil shear of straw without turnover that was16.90%lower than that straw turnover;Aggressive turnover obviously lowered the shear force of the deep soil.The shear force of no tillage that was 72.15% lower than that aggressive turnover.According to the results,it found that tillage measures nearly had no influence on the soil nutrients,while the straw turnover significantly increased various fertility indexes of the soil;The straw turnover had unobvious effect on the soil water content and the topsoil temperature,while the aggressive turnover increased the water content of the soil.2.Straw turnover and tillage measures had significant effects on crop agronomic traits,pest and disease damages and yield profits,which could be specifically expressed as: there was nearly no effect of straw turnover on tiller and plant height of wheats;Yield of wheats processed by straw turnover was slightly inferior to that processed by not turnover.Tillage measures have large effects on the growth and development of corns and peppers larger than that of straw turnover.Stem diameter and ear length processed by no tillage of corns were larger than that of peppers;However,the straw turnover increased the weight of fruits of single pepper;Scab ratio of peppers processed by no tillage was large,while straw turnover had no obvious effect on that;The yields of corns were insignificant(P> 0.05)among each processing;The highest one was 3598.48 kg / hm~2 of no tillage.The yield of peppers reached significance(P= 0.041)on whether it was turned over or not.The yield of hot pepper processed by turnover was significantly larger than that processed by non-turnover.The highest yield of pepper was 9103.20kg/ hm~2.Regarding the overall economic benefits,the highest was 32767.42 yuan / hm~2 of "no-tillage+ straw turnover",followed by 31364.95 yuan / hm~2 of "tillage 30 cm +straw turnover".3.Through researches on the agricultural production situation and farmers’ incomes in Yanshan,it showed that:(1)Agriculture extension in Yanshan County has achieved certain results.Extending projects covered soil testing and formula fertilizer,high-yielding cultivation and new agricultural machinery,etc.However,farmers have been not satisfied with the current extending works.Only 70% of surveyed farmers held attitudes of satisfaction on times and contents of extension;(2)Main factors limited the improvement of agricultural extension in Yanshan County: old farmers,low level of education and different backgrounds of various nationalities,etc.(3)It is suggested that the agricultural stations and relevant departments should intensify supervision,sound and extend the system,increase the scientific research,actively develop agricultural technologies,encourage diversified promotion,implement innovative and effective extension methods and constantly enhance the cultural quality of agricultural extension personnel as well as farmers to ensure smooth progress and efficient implementation of agricultural extension.All in all,agricultural extension works in Yanshan County have made some achievements,but it should be further emphasized due to insufficient extensions caused by many reasons.