Effects of Sowing Depth and Sowing Equipment on Growth and Yield of Mechanized Sowing Maize

Taking Zhongyu 3 as the experimental variety,this paper analyzed the effects of different sowing depths(5 cm and 8 cm)and sowing equipment(ZHSB-10 medium-sized sowing machine and 2B-2 small sowing machine)on the growth,yield and components of yield of mechanized sowing maize,to provide references for mechanized maize production in southwest ecological zone.The results showed that the germination rate,plant height uniformity,and most agronomic traits of maize plant were higher at the sowing depth of 5 cm;with the growth of the maize,the effects of the sowing depth on agronomic traits of maize gradually declined;the effects of the sowing depth on the empty stalk rate,double ear rate,lodging rate,and lodging and stem broken rate were smaller;the sowing depth of 5 cm could increase the yield of mechanized sowing maize and most yield traits of maize.Different sowing machines had smaller effects on the germination rate,plant height uniformity,and agronomic traits of all growth stages,empty stalk rate,double ear rate,lodging rate,lodging and stem broken rate,yield,and components of yield of mechanized sowing maize.

Influences of mechanized tillage and sowing modes on soil physical properties,soybean yield and economic benefits in mollisols region of Northeast China

Appropriate mechanized straw returning and tillage sowing techniques were effective means to optimize soil physical properties and enhance agricultural productivity,as well as important measures for the conservation and restoration of mollisols region in Northeast China.Under the condition of full-scale maize straw returning,four mechanized tillage and sowing modes were set,including plough tillage and sowing(PTS),combined tillage and sowing(CTS),no-tillage and sowing(NTS),and no-tillage and sowing with straw mulching(NTSM).In 2020 and 2021,the study investigated the effects of different mechanized tillage and sowing modes on soil physical properties,soybean yield and economic benefits.The results showed that during the pod-setting and pod-filling period of soybean,the NTS and NTSM treatments exhibited better effects on deep soil insulation and shallow soil moisture retention,the soil physical structure of PTS and CTS treatments were relatively ideal.Compared with PTS and CTS treatments,NTS and NTSM treatments significantly increased soil gravimetric water content(SWC)by 2.35%to 7.98%in the 5-15 cm soil layer and increased soil temperature(ST)by 3.94%to 10.42%in the 25-35 cm soil layer(p<0.05),significantly increased soil bulk density(SBD)by 2.98%to 6.72%and significantly reduced soil total porosity(STP)by 3.88%to 6.53%in the 5-25 cm soil layer,and significantly reduced soil gas phase ratio by 8.26%to 6.27%at the 15-25 cm soil layers,which caused soil three-phase ratio(STPR)of PTS and CTS treatment in 15-25 cm soil layer were relatively ideal.The soybean yield of NTSM treatment in 2020 was not significantly different from PTS and CTS treatment(p>0.05),the soybean yield of NTSM treatment in 2021 significantly increased by 7.30%and 5.84%over PTS and CTS treatments,respectively.And the average annual profit per unit area of NTSM treatment increased by 12.84%,12.41%and 8.57%compared with PTS,CTS and NTS treatments,respectively.Therefore,it was recommended to combine NTSM technique with PTS or CTS technique in a maize-soybean rotation system in mollisols region.The research results provided reference for the selection of appropriate mechanized tillage and sowing techniques in Northeast China’s mollisols region and had important guiding significance and practical value for the construction of rational plow layers and the implementation of conservation tillage.

Effects of Key Agricultural Measures of Mechanized Direct Seeding Technology on Rapeseed Yield in Chengdu Plain

Mechanized direct sowing of rapeseed is a labor-saving and highly-efficient culture technique. In order to explore high-yield cultivation techniques suitable for Chengdu Plain, effects of several key agronomic measures＇, such as sowing date, density and N fertilizers, on development and yield formation were studied by strip and split plot experiment of three factors. The research showed that optimal condi- tions for direct seeding technology can be achieved provided with scientific sowing date, density and appropriate N fertilizers, and the research showed that rapeseed yield reached the peak at 320 g/m2, when sowing date was on September 3th, sow- ing density was 30 plant/m2, and nitrogen fertilizer was 27 g/m2.