Water Use Characteristics Of Maize/Pea Intercropping Under Reused Plastic Film Mulched In Previous Year

Intercropping has been widely applied in the Hexi Oasis Area due to more effective use of resources and high productivity. However, the planting pattern is facing enormous challenges because the serious shortage of water resources, intercropping- saving mechanism and technology research study is an urgent need. Plastic film mulching has significant water- saving, increasing production effect, but excessively using of plastic film will increase investment, while causing serious pollution of the ecological environment. How to reduce the use of plastic film is an urgent need to solve the problem of agriculture in the oasis irrigation area under the condition of limited water supply to ensure the yield of crops. The planting pattern of corn intercropping pea is the research object this study, integrating application old plastic film recycling and limited water supply technology is the breakthrough point, through field experiment, the spatial and temporal changes of the influence factors of water use efficiency of maize/pea under the integration technology were discussed, to reveal the competition and complementary effect of crop species during the symbiotic period, and to clarify the mechanism of water saving, stable production and film reduction of a film for two years, Providing a theoretical basis to use as a crop without reducing resources under the limited water supply. Main conclusions are as follows:1. Maize-pea intercropping of a film two years with no tillage technology(NTMP) compared with traditional film(CTMP), can significantly improve soil moisture before the sowing, 0-50 cmaverage soil containing water of a film two years corn belt compared with the traditional film mulching corn belt up to 25.82%. In addition, irrigation and planting patterns have a great influence to soil moisture content of 0-30 cm and 30-120 cm soil layer, and plastic film mulching on the influence is not significant.Symbiotic period of maize and pea, a film two years corn belt water potential was significantly higher than pea belt, that of water migration from the corn to pea belt.In the high, medium and low three water supply levels,the average moisture migration were 22.7mm,30.7mm,25.0mm; But after peas harvest, pea belt water potential was significantly higher than that corn, water from peas to corn belt migration, migration 33.5mm,39.4mm,31.6mm. Meanwhlie, compared with the traditional film, a film has weakened the complementary utilization of water in the symbiotic period, the water in the irrigation zone is the largest mutual compensation effect.2. Compared reused plastic film mulching with the traditional plastic,the warming effect of a film two mulch has relatively low during the sowing to jointing stage, but there was no significant difference both them temperature effect at the late crop, soil temperature during the whole growth period is mainly affected by the planting pattern and water level, different mulching on temperature less impact.3. A film two mulch has a considerable effect in the suppression of Farmland Evaporation on farmland, compared with the traditional film, intercropping can increase the water consumption of maize and pea, but also reduce the proportion of evaporation(E/ET), intercropping E/ET of a membrane with two in different irrigation levels(high, medium,low) respectively decreased 15.17%, 12.66%, 7.65% than that of the weighted average in corresponding monoculture; the evaporation of intercrop system were low 9.43%,11.34%,15.98% than that of weighted average monoculture maize and monoculture pea. A negative correlation was observed among dry matter, LAI and E/ET, so intercropping can improve crop leaf area index, increasing the coverage of the surface can effectively reduce the amount of evaporation between farmland trees, that is to reduce the E/ET, and thus improve the efficiency of water use.Reused plastic film mulched exacerbated the pea on corn competitiveness and interspecific competition enhanced with the increase of irrigation level, interspecific competition maximum under medium irrigation treatments, at the same time, maintaining the suitablesize competitiveness in intercrop system was beneficial to reduce evaporation accounted for the proportion of total water consumption. In addition, after peas harvested, intercropping corn showed a strong recovery effect, comtrasting a film two years with the traditional film has strengthened has strengthened the compensation effect of intercropping maize.4. Intercropping of a film two mulch can improve the crop yield and water use efficiency, different treatments LER were greater than 1, indicated that intercropping has significantly increased the yield of maize and pea. Under high, medium and low water level, mixed crop yield of a film two years respectively increased 42.5%, 42.0%, 29% than that of weighted average in corresponding monoculture; Intercropping WUE is respectively high 25.90%, 29.5%, 20.79% than that of weighted average in corresponding monoculture. Compared a film two years with maize monoculture and intercrop yield in high, irrigation with traditional film has a considerable effect, but under low irrigation treatments higher than traditional film.A positive correlation was observed among yield and WUE of different treatments and water consumption, dry matter, and LAI, the two were negatively correlated with E/ET. It shows that increasing the leaf area index and reducing the proportion of the total water consumption(E/ET), is the basis of increasing water use efficiency and increasing yield.