Research On Soybean Whole Plastic-Film Mulching On Double Ridges And Planting In Catchment Furrows Technique And Water Retention And Warming Effect

Soybean being one of traditional food crops and cultivated in Gansu for a long history has anannual planting area of about135,000hm². As a typical dry farming province hit by drought9years outof10, Gansu has been suffering from droughts and less rainfall which cause long-term low and unstablesoybean yield and serious impact on the farmers’ income and growing enthusiasm.In order to solveanti-drought cultivation technique in Eastern Gansu, increase average yield and economic benefit, andpromote soybean industrialized development, whole plastic-film mulching on double ridges andplanting in catchment furrows technique （WPMT） was applied in soybean. Since experimentalresearches on matched and key cultivation skills such as suitable cultivars, sowing date, density,fertilizer rates, etc., and temperature and water effect were implemented, the results were as follows:1. Through variety selection trials, Zhonghuang No.41could be used as optimal spring variety ineastern dry tableland of Gansu by WPMT.2. Thorough analysis on growth process, growth period and output, optimal sowing date of springsoybean grown in eastern dry tableland of Gansu by WPMT was in late April.3. Through different plant density trials, the optimal sowing date of spring soybean grown ineastern dry tableland of Gansu by WPMT was6380plants per Mu（1Mu=667m²）.4. Through different formulae of fertilizer N, P and K experiments, the optimal application of N,P2O5, and K₂O were respectively4.6kg,4.2kg and2.5kg per Mu by WPMT.5. Research on soybean soil moisture effectiveness by WPMT demonstrated that the soil watercontent and capacity values in the depth of0cm to100cm at different growth periods by WPMT werehigher than by whole plastic flat mulching, and significantly higher than by half plastic mulching andopen field. As for water utilization efficiency, WPMT being the highest of11.18㎏/㎜·hm²was2.73㎏/㎜·hm²higher than CK, open field drilling of8.45㎏/㎜·hm², and3.64㎏/㎜·hm²higher than commonhalf plastic mulching of8.92㎏/㎜·hm².6. Research on soybean soil moisture effectiveness by WPMT indicated that concerning soiltemperature value in the depth of0cm to20cm at all growth periods, WPMT＞represents whole plasticflat mulching＞whole plastic-film mulching with soil covering and hole sowing＞half plastic mulching＞open filed. The soil temperature value in the depth of0cm to20cm at seedling stage by WPMT was2.0～4.6℃greater than by half plastic mulching and2.9～5.1℃greater than by open field. The soiltemperature value in the depth of0cm to20cm at branching stage by WPMT was1.6～2.9℃greaterthan by half plastic mulching and2.6～4.5℃greater than by open field. The soil temperature value inthe depth of0cm to20cm at flowering stage by WPMT was0.9～2.3℃greater than half plasticmulching, and3.5～5.2℃greater than by open field.7.The output results at different mulching modes showed that WPMT had the highest yield of232.72㎏／667㎡which was45.78%higher than open field and differed significantly. Wholeplastic-film mulching with soil covering and hole sowing was the second of221.63kg／667m²which was45.78%higher than open field and differed significantly. Whole plastic flat mulching was the third,half plastic mulching the fourth, and open filed the least.