Studies On Decomposed Effects Of Intercepted Wheat Straw On Properties Of The Yield And Quality Of Aquatic Vegetables In Plastic Tunnel

With the rapid development of China’s facility vegetable industry,the problem of unbalanced soil nutrients,soil acidification,salinization and continuous cropping obstacles has become increasingly apparent,which has become a major factor hindering its development.Planting aquatic vegetables in the facility or planting aquatic vegetables with sufficient moisture on the soil surface can both alleviate soil salinization effectively.China is a big agricultural country,and it produces a large amount of crop stalks each year.Crop stalk is rich in organic matter and has a large number of nutrient elements which can be utilized.Therefore,the utilization of stalks has attracted much more attention.Straw burning and disorderly stacking in the field obviously violate the sustainable development of resources.Therefore,direct straw returning is the most convenient and most effective way to use straw.In this experiment,aquatic vegetables were planted in the facility and the soil surface was covered with wheat stalks.High-temperature,high-humidity and aerobic fermentation were used to speed up the straw decomposition and to improve soil properties as well as the yield and quality of vegetables in the current season.The study was also aimed to determine the decomposition quantity of wheat straw under different returning amount and different lengths,so as to provide a theoretical basis for the efficient utilization of wheat straw and the replacement of fertilizers with organic manure in vegetable fields.The main research results are as follows:1.From November 2015 to April 2016,during the low-temperature season,the soil surface was covered with wheat straw at 500kg/mu,which were cut into small segments of 10 cm,and then watercress was planted on the surface(Nasturtium officinale R.Br).The maximum conductivity of surface water layer was 1180.7 μS.cm-1,the lowest value of surface layer water-surface oxidation-reduction potential was-80 mv,and after decomposition for 140 days,the decomposition rate of wheat straw was 66.67%;The yield of the first watercress harvested was lower than the control,while it was higher than the control at the 2nd and 3rd times,and the yield of the treated group showed an upward trend.The content of phosphorus and potassium in watercress was higher than the control group.The contents of VC,soluble protein,soluble sugar,brass,total phenol and other nutrients in watercress were better than those in control group.Compared with the control group,the treatment group increased the content of soil organic matter,total nitrogen and total potassium,and the decline of total potassium is lower than the control group.The results showed that the soil surface cover after wheat straw section can increase the decomposition rate,increase the yield and quality of watercress and fertilize the soil.2.From April to October of 2016,in view of the low temperature over-winter,stubble test wheat straw has a high decomposition rate,so the experiment increases the return amount of the wheat straw at 1000 kg/mu.The maximum conductivity of ground water layer of vegetable(Ipomoea aquatica Forsk.)was 1806 μS.cm-1,and the lowest value of surface water layer was-180.3 mv.After 163 days,the decomposition rate was 85.00%;The total yield was higher than that of the control.The contents of VC,Brass,DPPH radical scavenging rate of the water leeks were better than the control,and the content of soil organic matter,total phosphorus and total potassium were also increased.This results showed that the addition of aerobic fermentation in the high temperature and high humidity environment is more conducive to the wheat straw decomposition.3.From March to July of 2017,wheat stalks were cut segments and planted with water spinach.Treatment 1 is 10 cm and treatment 2 is 15 cm,after 129 days of decomposition,the decomposition rate of wheat stalk was 78.77%and 77.57%;The total water spinach yield was both higher than the control,among which treatment 1 is higher than treatment 2.The content of VC and soluble sugar in treatment 1 was higher than that in treatment 2,both of which was higher than the control.Soil organic matter content of treatment 2 is higher than treatment 1.The NO3-content treatment was significantly lower than the control.This indicates that the shorter the length of wheat straw is,the more beneficial the decomposition of straw is,and has the more significant effect on the the yield and quality of water spinach.Under the high temperature environment of the facility,the decomposition rate of wheat straw tested in the high temperature season was significantly higher than that in the low temperature season.In the high temperature season,wheat straw was added back to the field,and the effect of soil nutrient content supplement was better.The decomposition rate of wheat straw covered with 10 cm was higher than that of wheat straw covered with 15 cm.Wheat straw returned to the field with different amounts all could increase soil organic matter content and increase soil total nitrogen,total potassium and rapid available phosphorus.The nitrate nitrogen content in the soil was also reduced when wheat straw segments were returned to the field.