秸秆覆盖条件下播种的土壤临界含水率试验

Soil Critical Moisture for Seeding under Straw Mulching

通过室内外试验 ,对秸秆覆盖条件下播种的土壤临界含水率进行了试验研究。结果表明 ,在试验盆用塑料薄膜覆盖的条件下 ,测得玉米种子发芽出苗的土壤临界含水率为 1 4 % (体积含水率为 0 .2 0 0 2cm3 ·cm-3 )。由室外试验建立秸秆覆盖条件下耕层土壤水分运动规律的数学模型 ,经过数值模拟得到田间播种的临界含水率 :无覆盖的土壤重量含水率为 1 4 .89% (体积含水率为 0 .2 1 2 9cm3 ·cm-3 ) ,5cm厚麦秸覆盖的土壤重量含水率为 1 4 .36 % (体积含水率为 0 .2 0 5 4cm3 ·cm-3 ) ,8cm厚麦秸覆盖的土壤重量含水率为 1 4 .5 7% (体积含水率为 0 .2 0 83cm3 ·cm-3 )。这说明秸秆覆盖条件下播种的土壤临界含水率比裸地的低 。

Soil critical moisture for seeding under straw mulching was studied.The results showed that soil critical moisture for germination of corn grown in pot is 14% under the plastic film. Mathematical model for soil moisture movement of plough horizon under mulching is established with the outdoor experiments, and the critical moisture for seeding was achieved throngh using numerical simulation. The results indicated that soil critical moisture under mulching is lower than that without mulching, so the method of mulching benefits anti-drought seeding in arid areas.