陇东旱塬地区冬小麦水肥效应耦合模拟研究

SIMULATION OF EFFECTS OF NITROGEN APPLYING IN DIFFERENT RAINFALL ON DRYLAND WINTER WHEAT IN LONGDONG

采用无底铁框作微区，选择冬小麦生育期降水量（Ｐ）和施氦量（Ｎ）进行水肥效应模拟研究，得出冬小麦产量（Ｙ）与降水量和施氮量的关系为Ｙ＝２５０５．６７１３＋５．３４２２Ｎ－０．０２５１Ｎ￣２＋２４．３４８２Ｐ－０．０３２５Ｐ￣２＋０．００７４ＮＰ。水肥耦合方程为Ｎ＿ｃ＝７３．４８０５＋０．２３２５Ｐ。当降水量由１６０ｍｍ增至４００ｍｍ时，最高产量由５９９３．９３ｋｇ／ｈｍ￣２提高到７７１０．３９ｋｇ／ｈｍ￣２，最高产量施氮量Ｎｍａｘ由１２６．５１ｋｇ／ｈｍ￣２增至１６５．４８ｋｇ／ｈｍ￣２，经济施氮量Ｎ＿ｏｐｔ由７８．６０ｋｇ／ｈｍ￣２增至１０７．１２ｋｇ／ｈｍ￣２，Ｎ＿ｃ值则由１１０．５５ｋｇ／ｈｍ￣２增至１６６．５０ｋｇ／ｈｍ￣２。在降水量小于４００ｍｍ时有Ｎ＿ｏｐｔ＜Ｎ＿ｃ＜Ｎ＿ｃ＜Ｎ＿ｍａｘ成立，且Ｎ＿ｏｐｔ与Ｎ＿ｃ差值较大，说明旱塬地区单以经济施氮量为施肥标准不能充分发挥降水的增产潜力。提出了以上壤水肥宏观调控的原则，编制出陇东旱塬地区冬小麦合理施肥的方案。

The precipitation in winter wheat growth season and nitrogen applying were studied 50×50×100 cm isolated soil columun was used in experiment.The relation of yield with precipitation and nitro-gen rates could been fitted by Y = 2505. 6713+5. 3422N-0.025IN￣2+24. 3482P-0.0325p￣2+0.0074NP If N = Y/ P, the formula that nitrogen rates coincided with precipitation in winterwheat growth peried was N_c= 73. 4805+0. 2325P. When precipitation incrcased from 160mm to400 mm , the maximum yield would increase from 5993.93 kg/hm￣2 to 7710. 39 kg/hm￣2 , the maxi-mum nitrogen rate would increase from 126.51 kg/hm￣2 to 165.48 kg/hm￣2 , the optimum nitrogen ratewould increase from 78. 61 kg/hm￣2 to 107.12 kg/hm￣2.N_(opt)<N_c<N_(max) was trun on P<400 mm con-dition, Winter wheat fertilizer application consultsystem in Longdong area was programed as a soft-ware with simulating results and other experiment result.