不同施肥方式对河套灌区春小麦光合特性及产量的影响

EFFECT OF DIFFERENT FERTILIZATION SYSTEMS ON SPRING WHEAT AND PHOTOSYNTHESIS CHARACTERISTIC AND YIELD IN HETAO IRRIGATION DISTRICT

土壤中养分的均衡供应是限制植物生长和形成产量的首要因素。为确定河套灌区春小麦合理的施肥措施,本研究设置了不追肥(A0,对照);分蘖期和拔节期分别追施尿素225 kg/hm^2和150 kg/hm^2(A1);分蘖期追施尿素225 kg/hm^2、拔节期追施腐植酸150 kg/hm^2(A2);分蘖期追施腐植酸150 kg/hm^2、拔节期追施尿素225 kg/hm^2(A3);分蘖期和拔节期分别追施腐植酸225 kg/hm^2和150 kg/hm^2(A4)5种施肥处理对春小麦光合作用及产量进行研究分析。结果表明,A2处理可以有效提高春小麦各生育时期叶面积指数,其中成熟期较A0处理提高了23.8%。施用腐殖酸提高了春小麦各生育期净光合速率、气孔导度、蒸腾速率,降低了胞间CO2浓度,其中以A2处理促进作用最为明显。生育期内,A2处理维持较高的叶绿素含量的时间较长,且叶绿素a的含量下降比叶绿素b的含量要快。A2处理显著增加了春小麦的穗数和千粒重,进而显著提高经济产量。可见,适时、适量的腐殖酸与化肥配合施用可显著促进河套灌区春小麦生长发育、光合效率及最终产量。

The balanced supply of nutrients in soil is the primary factor limiting plant growth and yield. To determine rational fertilization measure of spring wheat in Hetao Irrigation District,Our experiment was established five treatments with no dressing（ A0）;topdressing by 225 kg/hm^2 and 150 kg/hm^2 of urea at the tillering and jointing stages,respectively（ A1）; topdressing by 225 kg/hm^2 of urea at the tillering stage and 150 kg/hm^2 of humic acid at the jointing stage（ A2）; topdressing by 150 kg/hm^2 of humic acid at the tillering stage and 225 kg/hm^2 of urea at the jointing stage（ A3）; topdressing by 225 kg/hm^2 and 150 kg/hm^2 of humic acid at the tillering and jointing stages（ A4）,respectively to examine growth and development and photosynthetic Characteristics of spring wheat in Hetao irrigation district. The data showed that A2 treatment can improve leaf area index of spring wheat in each growth period effectively,which increased by 23.8% compared to that in A0 treatment in harvesting. The increasing of stomatal conductance（ Gs）,transpiration rate（ Tr） and decreasing of intercellular CO2 concentration（ Ci）,were affected by humic acid with different degrees at flowering and fruiting growth stages and A2 treatment gave the best effects. A2 treatment maintained a longer time of higher chlorophyll content in the whole growth stage,compared with A0 and other treatments,and that the content of chlorophyll a decreased more quickly than that of chlorophyll b. Moreover,A2 treatment can significantly increase the number of spike and thousand seed weight of spring wheat,so significantly improve the economic yield of spring wheat. It is thus clear that the timely and moderate application of humic acid and chemical fertilizer could significantly promote the growth and photosynthetic efficiency of spring wheat in Hetao irrigation area.