配施钾肥、有机肥对旱地春玉米光合生理特性和产量的影响

以长期定位施肥试验为平台,研究在施用氮磷肥条件下,配施钾肥、有机肥对黄土塬区春玉米光合生理特性和产量的影响.结果表明:配施钾肥在灌浆前期降低了LAI、WUE、叶片水势、干物质积累量、叶片光合和蒸腾速率,但在灌浆后期提高了LAI、WUE、干物质积累量和叶片光合速率,且与对照间达显著差异,这说明配施钾肥对春玉米生长的影响主要表现在生育后期;配施钾肥可显著提高整个生育期的SPAD(叶绿素相对含量)、株高;可促进同化向籽粒的转移,使籽粒产量增加;但收获指数下降了3.2%.而配施有机肥可显著提高春玉米整个生育期的LAI、株高、SPAD、光合速率和蒸腾速率等生理指标(WUE和水势除外)和产量,使籽粒产量和生物产量增加,与对照、钾肥间差异均达到显著水平(P<0.05).在富含钾素的黄土塬区,配施有机肥对春玉米光合生理特性和产量的作用优于配施钾肥.

Effects of Potassium and Organic Fertilizer on Photosynthetic Physiological Characteristics and Yield of Spring Maize in Dry Lands

Field experiments were conducted to investigate the effects of potassium and organic fertilizer on photosynthetic physiological characteristics and yield of spring maize in phosphorus and nitrogen fertilizer application to an experimental field on the Changwu tableland of the Loess Plateau.Results showed that application of potassium fertilizer decreased the LAI,leaf water potential,dry matter accumulation,and leaf photosynthetic and transpiration rate before the filling stage,but increased the LAI,dry matter accumulation,and photosynthetic rate after the filling stage.The difference was significant in contrast to CIA.This indicated that the effects of potassium fertilizer on spring maize mostly occurred at the later growing stage.In contrast to CK,the effects could significantly incxease SPAD and plant height through the whole growing stage,incxease grain yield by 844.8 kg/ha,or 10%,and reduce harvest index by 3.20%.However,application of organic fertilizer could significantly increase the LAI,plant height,SPAD,photosynthetic and transpiration rate(except leaf WUE and water potential),and yield,and incxease grain yield by 687.8 kg/ha,or 20.0%.Application of orgenie fertilizer could raise biomass yield by 11025 kg/ha,or by 18.7%,with the harvest index reaohing to 48.8%.The aplication of organic fertilizer for hiomass yield had significant difference(P<0.05) in contrast to CK and potassium fertilizer application,increasing 6.5% and 9.7%,respectively.The effects of organic fertilizer on photosynthetic physiological characteristics and the yield were greater than those of potassium fertilizer in the tableland of enriched potassium,but application of potassium and organic fertilizer had no significant effects on the leaf WUE.