Research On Spatial And Temporal Variation Of Soil Nutrients Covered By Water-permeability Plastic Film

In addition to the function of common membrane water retention and temperature increase,the water-permeable plastic film also has the advantages of water seepage,ventilation,and temperature adjustment,which creates a better growing environment for the roots of crops and facilitates crop yield increase.As an important agronomic yield increase measure,the water-permeable plastic film cover has been widely used in agricultural production in China.Researching the characteristics of spatio-temporal changes of soil nutrients covered by water-permeable plastic film is the theoretical basis for maximizing crop yield increase.This study was based on the tracking field experiment of soil nutrient content from 0 to 300 cm depth.The comparison of non-coverage and normal mulch film coverage was used to study the distribution characteristics and changing trends of soil nutrients in maize growth period under the condition of water-permeable plastic film mulching.The SPSS software was used to analyze the differences in soil nutrients under different cover treatments.At the same time,the benefits of yield increase in the three experimental plots were analyzed.Finally,the temporal and spatial characteristics of soil nutrients under the mulching membranes were obtained.The conclusions are as follows:(1)The water-permeability plastic film coverage affects the distribution of soil nutrients on the 0-300 cm vertical profile,which is reflected in the distribution of soil nutrients on the profile and the level of soil nutrient content.Among them,the water-permeability plastic film has little influence on the distribution of soil nutrients.At the same time,the distribution of soil nutrient in the water seepage membrane is basically the same as that of bare land and common film(excluding alkaline nitrogen,ammonium nitrogen and available phosphorus).The water-permeability plastic film coverage has a great influence on soil nutrient content,especially soil nutrient content in the root zone and near root zone.The soil nutrient content in the water-permeability plastic film in jointing stage and tasseling stage is generally lower than that in ordinary membrane land or bare land,except for the alkali-hydrolyzable nitrogen in the tasselling stage;the gap between soil nutrient in the water-permeable membrane land and nutrients in the bare land and common membrane in mature stage is reduced,even beyond the bare soil,ordinary film soil nutrients(such as: total nitrogen,alkaline nitrogen,nitrate nitrogen and available phosphorus).(2)The change of soil nutrient infiltrating with water-permeability plastic film affects the trend of soil nutrients during the growth period of maize.It is manifested in the change trend of soil layers.The nutrient of 0-200 cm soil infiltration membrane in jointing stage and tasselling stage is affected by the consumption of maize,and the decrease is more significant than that of naked.Land(such as organic matter,total nitrogen,nitrate nitrogen,available potassium);Maize has less demand for soil nutrients during mature period,and at the same time it receives different compensation(nutrient conversion and release,nutrient migration,nutrient mineralization,etc.).Soil nutrients in the water-permeability plastic film have rebounded,even higher than bare land,common membrane land(such as alkaline nitrogen,nitrate nitrogen,available phosphorus).The 200-300 cm soil layer of the water-permeability plastic film is outside the main distribution area of the crop root and is affected little by the absorption of maize.However,due to the influence of soil water and heat conditions,nutrient conversion,and other changes,the increase and decrease vary.(3)In general,at the significant level of p=0.05,the difference of the soil nutrient among the water-permeability plastic film,the bare land and the ordinary membrane land showed significant,indicating that the water-permeable plastic film coverage significantly affected the nutrient content in the 0-300 cm soil layer,but the specific impact of the performance on the soil nutrients varies,either increasing or decreasing.This paper compares the plant height of maize under the same time and different treatments to indirectly determine the amount of soil nutrient absorbed by the three treatments.The default plant height is positively correlated with the absorption of nutrients.This indirect connection is a bit far-fetched and not as direct comparison to the nutrient content of each treated corn plant.The direct comparison is more convincing then that indirect connection.So this study is still insufficient in this respect.In future experiments,the content of nutrient elements in maize plants should be measured simultaneously in order to more fully analyze the effects of mulching on soil nutrient content.