水氮处理对青花菜产量及水肥利用效率的影响

Effects of Water and Nitrogen Treatment on Yield , Water and Soil Nutrition Use Efficiency of Broccoli

采用大田试验方法,研究了不同灌水量和不同施氮量对西北高原青花菜产量、水分利用效率和根际土壤速效养分含量的影响。结果表明:青花菜产量以中水高氮(W2N1)处理最高,达2035kg·(667m2)-1,较产量最低的低水低氮(W3N3)处理高36.30%;而水分利用效率随灌水量的减少而显著提高,低水高氮(W3N1)处理的水分利用效率最高。青花菜各器官的干物质积累量随着水氮施用量的增加大体呈增加的趋势,但超过一定量后则表现为下降的趋势,以中水高氮(W2N1)处理最高。不同水氮处理下0～20cm土层碱解氮、有效磷、速效钾含量都呈先上升后下降的变化趋势,且磷钾肥的施用量远大于吸收量,土壤残留较多。综合评价,西北高原青花菜种植以中水高氮(W2N1)处理效果最佳,即施氮量为27.6kg·(667m2)-1、灌水量为83.52m3·(667m2)-1。

Taking field test method,this paper studies the effects of different irrigation quantity and nitrogen application on yield,water utilization efficiency and root zone soil nutrition contents of broccoli(Brassica oleracea L. var. italica Plenck)planted at north-west plateau. The results showed that the yield of broccoli by treatment of medium water and high nitrogen(W2N1)was the highest. It could reach 2 035 kg·(667 m2)-1 ,which was 36.30% higher than low water low nitrogen treatment (W3N3).But,water utilization efficiency increased along with the decrease of irrigation quantity. The highest water use efficiency 35.08 kg·m-3 appeared with the low water high nitrogen treatment(W3N1). The dry matter accumulation quantity increased with the increase of water and nitrogen quantity,but it would decrease when their quantities exceeded certain dosage.Medium water high nitrogen treatment (W2N1)had the best effect.Under different water and nitrogen treatment,in 0-20 cm soil layer the contents of soil available N,P and K would nave the tendency of rising firstly,then falling down. The application quantity of P and K was even larger than their absorption,big quantity was left in soil.To put it short,planting broccoli in north-west plateau the best treatment is medium water high nitrogen (W2N1)- the nitrogen fertilizer applying quantity is 27.6 kg·(667 m2)-1 and irrigation quantity is 83.52 m3·(667 m2)-1 .