春小麦地膜覆盖穴播栽培技术增产效应分析

The Effects of Hole Seeding Technique with Mulching Plastic Film on the Yields of Spring Wheat

春小麦地膜覆盖穴播栽培技术具有显著的增产效应，比露地对照增产达４４．４％。全生育期地膜覆盖具有保墒和提高生育前期地温的作用，使覆膜小麦出苗早、整齐，促进营养生长，穗分化时间较长，灌浆充分，穗粒数和千粒重提高。地膜覆盖穴播小麦具有叶面积大、叶绿素含量高、光合“午睡”现象轻和干物质积累多的特点。在拔节期、孕穗期和灌浆期日平均光合速率为１．０８ｍｇＣＯ２／ｄｍ２．ｈ、１３．７０ｍｇＣＯ２／ｄｍ２．ｈ和１１．６２ｍｇＣＯ２／ｄｍ２．ｈ，分别比对照高２３．３％、３３．１％和１２．７％。在拔节期光合速率日变化为单峰型，而在孕穗期和灌浆期则为双峰型。净同化率最高可达１３．０１ｇ／ｍ２．ｄ，平均为８．２４ｇ／ｍ２．ｄ，比对照高０．３８ｇ／ｍ２．ｄ和０．２３ｇ／ｍ２．ｄ。

The cultivating technique of hole seeding with plastic film covering in spring wheat had significant effects in increasing yields than the outdoor wheat, the increasing rate of yield being 44.4 %. Due to the effects of preservation of soil moisture at the whole growing period and raising temperature at 0 20 cm cultivated horizonat the earlier period of growth by means of mulching plastic films ever all period of duration, an even emergence of seedings, earlier and hastened vegetation growth, elongation of the time of young panicle differentiation and intensity of grain filling that all raised grain number per ear and thousand kernel weight had been achieved Spring wheat by hill sowing with mulching plastic had possessed larger leave areas per plant and higher chlorophyll contents, lighter middle depression of photosynthesis on bright sunny days and more accumulations of dry matter than the control. The average net photosynthetic rates at shooting, earing and filling stage were respectively 1.08,13.70 and 11.62 mg CO 2/dm 2.h that was higher by 23.3,33.1 and 12.7 % than control at the same stage respectively. Diurnal variation of the net photosynthetic rate of wheat was mono peak type at the shooting stage, but double peak one at ear bearing and filling stages.