Effects Of Different Film Covering Time On Soil Hydrothermal Conditions And Maize Yield

Since the introduction of plastic film mulching technology into China in the1970s,it has become one of the important methods for yield increasing and water saving,and the application area of film mulching has continued to grow.Plastic film mulching technology plays an important role in water conservation,regulating soil temperature,improving soil structure,and increasing crop yield,and is of great significance for agricultural production in China.Long-term large-scale application of plastic mulching has brought benefits to agriculture.However the incomplete removal of the mulching film has also brought a huge burden on the environment at the same time.Residual plastic mulch not only pollutes the environment,destruct the soil structure,but also had a bad influence on the agricultural production.In order to both obtain the highest yield and reduce the environmental pollution from residual plastic film mulching.Our study was carried out at agricultural environment and land conservation scientific observation experiment station of the Ministry of Agriculture,Fuxin,Liaoning.We examined soil temperature,soil moisture and corn growth,and set different film removal time?including film mulching 30 days,film mulching 60days,film mulching 90 days,film mulching 120 days and fully film mulching?to simulate degradable plastic film degradation time points,to systematically study the effect of different film removal time on soil hydrothermal effect and corn growth,and hence provide theoretical reference and fundamental data for the optimized applying of plastic film mulching.The following conclusions are summarized based on our study:?1?The effect of different stripping time on the yield and water use efficiency of corn were different,among which M₉₀ treatment had the highest yield and water use efficiency.The yield of M₉₀ was 11469.27?kg.hm-2?,which was 14.55%,6.14%,3.14%,2.48%,and 2.79%higher than those of M₀,M₃₀,M₆₀,M₁₂₀,and M_quan,respectively.The yield was directly related to the ear length,ear diameter,ear row number,and grain number per row,100-grain weight of corn.M₉₀ was 0.81 cm,0.38cm,0.18cm,0.38cm and 0.58cm higher than M₀,M₃₀,M₆₀,M₁₂₀,and M_quan for ear diameter,and higher than 5.23g,3.93g,3g,2.07g,and 2.5g,respectively for100-grain weight,and 7 grains,5 grains,and 1 grain per row,0.33 grains,1.67 grains for ear rows;M₉₀ treatment in the ear line number higher than M₀ 1.89 lines,1.59lines higher than M₃₀,0.11 lines higher than M₆₀,0.29 lines higher than M₁₂₀,the difference between M₁₂₀ and M₉₀ is not significant.The ear length was 4.93 cm higher than M₀,4.47 cm higher than M₃₀,2.27 cm higher than M₆₀,and 0.37 cm higher than M_quan.The difference in M₁₂₀ and M₉₀ panicle length was not significant.The water use efficiency was M₉₀>M₁₂₀>M₃₀>M₆₀>M_quan>M₀.The use of mulching in the whole growth period has low water use efficiency and does not achieve the purpose of water saving irrigation.Covering the film for 90 days improve the yield and water use efficiency.?2?Soil temperature was in an appropriate range during the plant growth period under M₉₀ treatment.The temperature of soil was too high,and the corn yield was decreased due to premature removal of the film mulching,Moreover,The treatments covering film mulching more than 90 days lead corn to pre-aging and also reduce corn yield?3?Soil poundage was lowest for control during the corn grows;also soil poundage for premature removal of the film mulching treatment was not significantly higher than control.The soil poundage has been maintained at a high level under fully covered treatment.The soil moisture content of M₉₀ treatment can provide more sufficient moisture for maize during the early middle stage of corn growth,and it can contribute corn growth.During the middle and later stages of maize growth,especially after the grain filling stage,the soil moisture content is reduced due to the removal of the film,but it was not affecting the corn growth,and also effectively prevents the corn pre-aging,lodging and other risks of reducing corn production.?4?During the whole growth period,the growth performance in the treatment covering film mulching was better than that of the uncoated control corn.The earlier the film was uncovered,the more unfavorable for the corn growth.The continued covering of the film mulching after 90 days also negatively affected the corn growth performance.M₉₀ treatment is best for the corn growth.The plant heights of maize treated with different stripping time were:M₉₀>M₁₂₀>M_quan>M₆₀>M₃₀>control;M₉₀ was higher than M₀,M₃₀,M₆₀,M₁₂₀,M with 32%,23%,14%,3%,and 6%,respectively;The corn stem diameter was M₉₀>M₁₂₀=M₆₀>M_quan>M₃₀>M₀,the stem diameter of M₉₀ is 7.27 mm larger than M₀ stem.In summary,the soil temperature and soil moisture covered by the film for 90days provide a good environment and foundation for corn growth.From the leaf area,plant height and stem diameter,it can be seen that the coating is superior to other treatments for 90 days.The dry matter accumulation of the 90-day corn covered by the film was better than other treatments in terms of several basic indicators of yield.The yield of the film over the 90 days was better than that of other treatments,and the maximum value was obtained.At the same time,the water use efficiency of the film was highest in the 90 days.Film coating for 90 days is the best time for corn film coverage in this area.