平原区农田林网光强变化及其对小麦产量的影响

研究了豫东平原农田林网内光合有效辐射及其对小麦产量的影响,结果表明:杨树林带对作物遮荫影响在1倍树高范围内,1倍树高之外影响不明显;在第1点(0.1H,H为树高)、第2点(0.5H)和第3点(1H)的光强分别占第5点(3.6H,CK)光强的63.0%、88.2%、98.8%,第4点(2.6H)光强与第5点几乎相等;农田林网内不同时期遮荫效应依次是成熟期>灌浆期>开花期>苗期;各点日变化均呈单峰曲线,除第1点峰值出现在14:00,其余各点均出现在13:00;其中,成熟期各点光强日变化最明显;小麦产量呈现随试验点离林带距离的增加而增大的趋势,第4点产量最高,为966.43g/m2,对照点有所降低;小麦粒数变化与产量趋势一致,千粒重随距林带距离增加有增大趋势,但差异不明显;小麦产量和粒数与光强均呈正相关(P<0.05);小麦千粒重与光强关系不明显。

PAR Change of Farmland Shelterbelt and Its Effect on Wheat Yield in Plain Area

The photosynthetic active radiation(PAR) changes of farmland shelterbelt and its effect on wheat yield in eastern Henan plain were studied.The results showed that the effect of shelterbelt on crops occurred in the range of 1 time the tree height,and was not obvious outside it.The light intensity in first(0.1 time tree height),second(0.5 time) and third point(1 time) was respectively 63.0%,88.2% and 98.8% that of fifth point(CK),while the light intensity in fourth point was almost the same to CK.The shading effect of farmland shelterbelt on wheat at different stages was:mature stage>filling stage>blossom stage > seedling stage.The daily variation at different points all showed a single-peak curve and the peak value appeared in 13:00 except the first point which appeared in 14:00.The daily variation of light intensity at different points was the most obvious at mature stage.The wheat yield increased with the increase of distance to the forest shelterbelt,and the highest yield came from the forth point(966.43 g/m2),even a little higher than CK.The change trend of grain number was the same as yield.The thousand grain weight increased with the increase of distance to shelterbelt,but was not significant.The yield and grain number of wheat had positive correlations with PAR(P<0.05),and the thousand grain weight had no obvious relationship with PAR.