摘 要：
通过对施氮水平的控制,研究农田土壤水盐分布和向日葵的产量变化规律,为改善盐碱地作物生长环境,增加产量提供有效的理论依据.选取大同盆地,采用覆膜宽垄沟灌(G)和水平畦灌(Q) 2种耕作灌溉方式,设置3种施氮水平,施氮量分别为156 kg/hm2(N1)、260 kg/hm2(N2)、364 kg/hm2(N3),以平作不施氮(QN0)为对照组,五氧化二磷和氧化钾用量分别45.7和54.84 kg/hm2.灌溉定额为340 mm.结果表明:在不施氮条件下,沟灌垄上0~40cm电导率EC1∶5比水平畦灌电导率低15%~30%,沟中0~40 cm EC1∶5比水平畦灌低40%~50%.40 cm以下土层,沟灌土壤垄上和沟中EC1∶5比水平畦灌低20%~40%.而在施氮条件下,沟灌垄上0~40 cm表层EC1∶5和水平畦灌差异不显著(p<0.05),但随着施氮量的增加,二者表层EC1∶5都略微增加,沟灌沟中0~40 cm EC1∶5较水平畦灌低40%~60%.40 cm以下沟灌沟中EC1∶5比畦灌低40%左右.在相同的灌水量下,沟灌沟中0~40 cm表层含水率低于垄上覆膜表层含水率,而在整个生育期内除了降雨影响外,覆膜沟灌含水率均在10%~23%,与不施氮处理差异不显著(p<0.05).采用260 kg/hm2的施氮时,向日葵生长最优,盘径22.5 cm、千粒重192.30 g、籽粒产量4 893.8 kg/hm2.综上分析,采用覆膜沟灌且施氮量在260 kg/hm2左右能改善土壤水盐状况,提高作物产量.
作 者：
BAI Yu-long;JIANG Jing;ZHAI Deng-pan;ZHANG Peng;GUO Jun-lin;School of Hydraulic Science and Engineering,Taiyuan University of Technology;Institute of Agricultural Environment and Resources,Shanxi Academy of Agricultural Sciences;Shanxi Key Laboratory of Soil Environment and Nutrient Resources;
关键词：
sunflower;;nitrogen application rate;;conductivity;;water content;;yield
摘 要：
Through the control of nitrogen application level,the study of soil water-salt distribution and sunflower yield variation law was carried out,which provided an effective theoretical basis for improving the crop growth environment and increasing yield of saline-alkali crops. In this study,Datong Basin was selected,and two kinds of tillage irrigation methods were adopted,including wide ridge furrow irrigation (G) and horizontal flood irrigation (Q). Three nitrogen application levels were set,and the nitrogen application rate was 156 kg/hm~2 (N1),260 kg/hm~2 (N2),364 kg/hm~2 (N3),with no nitrogen application (QN0) as the control group,and the amounts of phosphorus pentoxide and potassium oxide were 45.7 and 54.84 kg/hm~2,respectively. The irrigation quota was 340 mm. The results showed that under the condition of no nitrogen application,the conductivity of EC_(1∶5) of 0 ～ 40 cm on the furrow irrigation ridge was 15% ～ 30% lower than that of horizontal border irrigation,and the 0 ～ 40 cm EC_(1∶5) in the ditch was lower than that of the horizontal border irrigation by 40% ～ 50%. For the soil layer below 40 cm,the EC_(1∶5) was 20% ～ 40% lower than that of the horizontal border irrigation. Under nitrogen application conditions,there was no significant difference between EC_(1∶5) on 0 ～ 40 cm surface layer of furrow irrigation and horizontal border irrigation (p<0.05). However,with the increase of nitrogen application,EC_(1∶5) in both surface layers increased slightly,and the 0 ～ 40 cm EC_(1∶5) in furrow irrigation was 40% ～ 60% lower than that in horizontal border irrigation. The EC_(1∶5) of furrow irrigation under 40 cm was about 40% lower than that of border irrigation. Under the same irrigation amount,the moisture content of 0 ～ 40 cm surface layer in furrow irrigation ditch was lower than that of the film-covered surface layer on the ridge,and in the whole growth period,except for the influence of rainfall,the moisture content of furrow irrigation with film-covered ditch was 10% ～ 23%,which was not significantly different from that without nitrogen application (p<0.05). Based on the above analysis,using plastic film mulching furrow irrigation with nitrogen application amount of around 260 kg/hm~2 can improve soil water and salt conditions and increase crop yield.
