【摘要】 在上海市宝山区月浦镇的露地菜田设置以直播小白菜为代表的叶菜田间施肥试验,对施氮量、施磷量、施钾量、基肥施用量、氮追肥运筹、叶菜相对产量等一系列试验数据进行相关统计分析,求取相应的数学模型,初步建立露地直播小白菜的推荐施肥量指标。结果表明:(1)建立露地直播小白菜推荐氮肥效应函数为y=-0.270 3x2+104.19x+1 588.4,相关系数R2=0.909 1。磷肥效应函数为y=-3.386 7x2+420.89x-744.05,相关系数R2=0.873 0。钾肥效应函数为y=-1.729 5x2+205.51x+5 859.6,相关系数R2=0.874 3。(2)推荐每公顷小白菜基肥施用NPK复混肥应不少于300kg/hm2,当小白菜长出3～4片真叶后,应及时追施氮肥,7～10d之后再追施1次,共折合尿素320kg/hm2。2次氮追肥配比为2∶1时较有利于生物产量的形成。整个生产过程总施纯N 195kg/hm2,P2O560～75kg/hm2,K2O 60kg/hm2。更多还原

【Abstract】 The leaf fertilizer trial with packchoi was conducted in open vegetable field in Yuepu town,Baoshang district,Shanghai city.A series of test data include the amount of nitrogen fertilizer,phosphorus fertilizer,potassium fertilizer,base fertilizer,nitrogen top-dressing and leaf relative yield were analyzed,the corresponding mathematical model was established,and the proper fertilization quantity of outdoor sowing packchoi was determined.The results showed that the function of nitrogen fertilizer,phosphorus fertilizer and potassium fertilizer were y=-0.270 3x2+104.19x+1 588.4(R2=0.9091),y=-3.386 7x2+420.89x-744.05(R2=0.8730),y=-1.729 5x2+205.51x+5 859.6(R2=0.874 3),respectively.The amount of NPK compound fertilizer as base manure was not less than 300 kg/hm2.Nitrogen fertilizer as dressing manure was proposed to be used after packchoi has 3~4 leaves.7~10 days later,nitrogen fertilizer was used again.The total nitrogen as dressing manure was 320 kg/hm2.The ratio of 2∶1 twice dressing manure benefited biological yield.Totally,195 kg/hm2 N,60~75 kg/hm2 P2O5,60 kg/hm2 K2O fertilizer were used in the process.更多还原