Effects Of Degradable Film Mulching On Soil Hydrothermal Regimes,growth And Yield Of Winter Wheat

The plastic film mulching can increase soil temperature and conserve soil moisture,but pollute field environment and destroy ecology.Biodegradable film has certain significance for coordination of farm production and field environment.Wheat production is group process.Adjusting row spacing is an important measure to change population structure.The field experiment were conducted by ridge-furrow planting of winter wheat “xiaoyan22”,plastic film and 2 biodegradable films mulch on ridge.There were 2 row spacing patterns,namely 3row and 4row(row spacing are 30 cm and 20 cm,respectively).Supplemental irrigation was in jointing stage.Convention planting with no film was control treatment(CK).Major research contents include soil temperature and moisture content,population dynamic,growth and physiological characteristics,yield and water use efficiency.This will contribute to improve the understanding of biodegradable film and find reasonable population structure and supplemental irrigation.The experiment in October 2015 to June 2016 and analysis finally showed following conclusions:(1)Film mulching can reduce the change of soil temperature in time and vertical space.Daily changing range of soil temperature was plastic film<3# biodegradable film(induction period is 210 days)<2# biodegradable film(induction period is 180 days).The change in vertical space of film mulching was smaller than no film.Film mulching on ridge can reduce the change of shallow soil temperature and increase average temperature of deep soil in furrow.The effects of biodegradable film fallen in between plastic film and no film.The difference of effects on soil temperature between plastic film and biodegradable film was small in different growth stages.(2)Film mulching made sensible water allocation in time scale.The soil water storage were,in order,plastic film>3# biodegradable film >2# biodegradable film> no film> CK before jointing stage and filling stage.Field evaporation after jointing stage under plastic film was smaller than 3# biodegradable film,2# biodegradable film and no film and CK were no less.Film mulching can reduce the ratio of soil evaporation to evapotranspiration,plastic film was more helpful than biodegradable film.Row spacing pattern had no effects on soil water storage and evaporation after jointing stage.Supplemental irrigation in jointing stage Increased water consumption,the effect lasted for a longer time in deeper soil and 4row lasted for a longer time than 3row.(3)Plant height under different films had not significant difference,film mulching was significantly taller than no film and CK,3row was taller than 4row.Film mulching and supplemental irrigation increased leaf area,plastic film was more helpful than biodegradable film,and 4row was more helpful than 3row.Supplemental irrigation increased dry matter accumulation,but film mulching didn’t.Dry matter accumulation under different films and row spacing partners had not significant difference.Chlorophyll content in different treatment had no significant difference in jointing stage,heading stage and maturity stage,but had significant difference in filling stage.(4)Film mulching was helpful to seeding emergence,but row spacing pattern wasn’t.Film mulching was helpful to tiller,plastic film was more helpful than biodegradable film,4row was more helpful than 3row.Supplemental irrigation increased the number of effective tiller 。 Film mulching was against grain weight increase in later filling stage.1000-grain weight in different treatment had no significant difference,but spike number and seeds per ear had significant difference.Film mulching can increase spike number,seeds per ear and yield.Plastic film was more helpful than biodegradable film,but not significantly,so that we can substitute biodegradable film for plastic film.Narrow row spacing and supplemental irrigation increased pike number,seeds per ear and yield,but not significantly.(5)Film mulching can increase water use efficiency significantly,plastic film>3# biodegradable film >2# biodegradable film,and the difference of plastic film and 2# biodegradable film was significant.Narrow row spacing and supplemental irrigation increased water use efficiency,but not significantly.Economic coefficient of 4row was significantly more than CK,but 3row wasn’t.Supplemental irrigation can reduce economic coefficient.Film mulching can increase economic coefficient,and biodegradable film was more helpful than plastic film.