Effects Of Different Mulching Materials In Autumn On Soil Moisture And Yield Of Spring Maize

Considering the technical problems caused by drought in the Northwest of China, the effects of three different cover materials [common plastic film mulching(PA), decompose film mulching(BA) and corn stalk(SA)] in autumn on soil moisture, soil temperature, maize development physiological characteristics and grain yield of spring corn were studied in two years with conventional tillage(CK) as control. Results showed that:1. Autumn mulching can significantly improve the soil water storage at planting time,and it also could effectively improve soil moisture conditions during earlier stage.Under different treatments, the evaporation of soil moisture during winter leisure period was all reduced and upper soil water content before sowing was increased significantly. Compared with CK, water storage within 0-200 cm soil under different treatments was also significantly increased. Soil water storage in treatments of PA, BA and SA was increased by 40.33 mm,42.47 mm and 58.25 mm on average, respectively. There was no significant difference in the soil moisture preservation between common plastic and decompose film. PA had the highest average soil water content between 0 to 200 cm during earlier growing stage(about sowing after 0 ~ 50 d) in two years, followed by BA, then SA and CK. There was no significant difference in the average soil water content in SA and CK, both of which were higher than BA and PA during late growing periods.2.Different cover material in autumn can improve the ground temperature(except SA).The average soil temperature in PA was higher than other treatments and that in BA and SA was higher than control during the whole growth period.The temperature at a certain soil layer in PA was higher than the other treatmwnts and that in SA and CK the lowest.3.The soil available N, P and K under different mulching materials were higher than the control after maize harvest, as manifested in upper soil layer, and the effect gradually decreased with the increase of soil depth(except SA).4.Results showed that different cover materials in autumn could improve plant height,stem diameter, leaf area and other important agronomic traits of the spring maize. PA had thegreatest effects on these agronomic traits among all the treatments, followed by BA and SA.Most treatments(except autumn covering straw) could significantly increase ear weight and its proportion in corn dry matter weight during mature stage.5. Different cover materials in autumn could improve the net photosynthetic rate(Pn),transpiration rate(Tr), stomatal conductance(Gs), maximum fluorescence(Fm) and the maximum photochemical quantum yield(Fv/Fm) in maize leaves, the potential activity of PS II(Fv/F0) and light chemical quenching coefficient(q P),and these agronomic traits were common plastic film(PA)>decompose film(BA)>corn stalk(SA)≈conventional flat planting(CK).6. Compared with the control, the production in PA, BA and SA was increased by44.26% ~ 74.60% 、 22.11% ~ 32.89% and 0.20% ~ 1.29%, respectively. The water use efficiency(WUE) of PA and BA was increased by 22.01% ~ 54.89 and 24.51% ~ 5.67%,respectively, however that in SA was reduced by 7.50%~16.01%.