| Sichuan is one of the major maize growing areas, meanwhile, maize production in the area has an important position in the agricultural economic development. And the important factors that restrict the increase of maize yield are rainy weather, less sunshine and seasonal drought which often happen in corn growth stage, especially the drought and cold temperatures in the growth and dry and high-temperature in the later period. Thus ridge and coverage measures appear in the production which can regulation growth micro-climate and field soil conditions, but research is lacking. Therefore, this study used cultivation variety ChuanDan "418", in experimental farm of Sichuan Agricultural University(in Ya’an),set up six levels:the no covering treatment (CK), flat planting with straw mulching (FST), flat mulching and planting of mulch film side (FFS), flat mulching and planting on top of the plastic film(FFT), half ridge tillage mulch film covering and planting of mulch film side (RFS),whole ridge tillage mulching and planting on the top of film (RFT) and other processing, explore the different mulching measures on maize growth and yield performance, nutrient absorption, and topsoil moisture, temperature and inorganic nitrogen changes, major results are as follows:(1) The mulch tillage treatments can improve maize plant growth, but with the growth promoting effect would gradually weaken. The plant height, leaf area, dry matter accumulation of FFT, RFS, RFT has promoting effect, the RFT treatment effect is optimal. The FST treatment in V12period began to promote plant growth. After silking stage, with FFT and RFT treatments maize growth rate has slowed down significantly. Each cover tillage increased aboveground dry matter accumulation, the RFS and RFT treatments increased by22.6%and15.0%compared with no cover treatment at harvest. In addition the harvest index, grain weight, ear rows have improved, the final grain yield also increased. In particular, grain yield of RFS, RFT and FST treatments increase of29.3%,20.5%and20.6%than no coverage respectively, RFS’s output was up to7602kg·hm-2(2) Maize plant nutrient uptake and transport could be promoted with different mulch tillage. Nitrogen, phosphorus, potassium accumulation of different organs and total accumulation have increased with plastic film mulching cultivations. But FST nutrient accumulation began to accelerate after V12period. After silking stage, nutrient from vegetative organs to reproductive organ volumes increased under each covering cultivations, but the RFT’s accumulation diminished capacity. To the harvest period, the RFS treatment has the highest accumulation of nitrogen, phosphorus compared with no-coverage treatment, increased to50.1%and51.7%, then the RFT increased by33.7%and33.8%. Hundreds of kilograms of grain nutrient requirement and PFP under different coverage of farming have some increase.(3) It has difference impact on soil moisture and temperature with different mulching tillage during maize growth. Coverage can increase the0-20cm layer soil moisture content. The average soil moisture content of RFT increased significantly15.5%silking stage, but the RFS treatment increased increased during the whole growth period was18.3%, and significantly improve the harvest period60-100cm soil moisture. Throughout the film covering the soil temperature of10cm soil layer increased and more obvious in sunny day. Membrane surface of FFT and FFS were easily affected by mud pollution. Before R3stage, soil temperature of RFT was highest in8:00,14:00,18:00, respectively increased by0.7～3.4℃,0.8～3.3℃,1.0～5.7℃,the highest temperature was32.4℃, the average is about30℃; And the temperature of RFS was low as1.0℃than RFT in each time which was in the range of18.8-29.6; The temperature of FST showed increased of0.5℃at8:00, and dropped0.5and0.8℃at14:00and18:00, it was cooling in fine weather, insulation in rains. The average temperature was increased by an average of0.2℃,soil temperature control in17.6～25.7℃.(4) RFS and RFT had the most obvious effect, the RFS treatment significantly improved0to20cm soil moisture°Content before silking, and10cm soil layer temperature was increased by0.7to5.7℃, even the maximum temperature was32.4℃which may lead to reduced root activity. RFS treatment could effectively utilize rainfall, so water content increased significantly in the whole stages,and soil temperature was controlled within18.8～29.6℃.FST treatment made the soil moisture content of0-20cm layer higher than the no-coverage significantly. It could keep the ground temperature in the rainy days, and be cool in sunny high temperature can cool down when the soil temperature is more stable control of17.6～25.7℃. No matter the weather was sunny or rainy, FST could maintain stability of the soil temperature within17.6～25.7℃,that was relatively stable.(5) Different mulching tillage could also affect the migration of soil inorganic nitrogen. FST, RFS and RFT treatments increased the content of the inorganic nitrogen significantly in soil. Soil ammonium nitrogen and nitrate content of0-20cm was increased significantly under FST, but RFS treatment increased which in0-60cm significantly.In the different mulching methods, crop growth and development, nutrient uptake, yield and soil moisture and temperature was synchronized and has difference.crop growth and development, nutrient uptake and yield and soil water temperature and mineral nitrogen is more synchronized and has difference under coverage farming. Different materials yield different mechanisms:plastic mulching promoted early growth stage, FST showed role after silking. Under our experimental conditions, mulching with ridge planting was better than flat planting, the straw mulch was conducive to the utilization of straw, also showed advantages in the production. Covering cultivation in increasing production at the same time enriching the soil fertility, is conducive to a continuous supply of soil fertility. |
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