Study On The Rates Of NPK Fertilizer And Stress Resistance Of Foxtail Millet

A pot experiment with “3414” incomplete orthogonal design wasperformed using foxtail millet JinGu21variety cultivar as material toelucidate the effects of the rates of NPK fertilizer under water supplywith different levels.To research the effect of coupling between saltand fertilizer on physio-morphological indices of foxtail millet atseedling stage, explore the relations NPK content and combinationswith the salt resistance of the foxtail millet. To research the effect ofcoupling between low temperature and fertilizer onphysio-morphological indices of foxtail millet at seedling stage,explore the relations NPK content and combinations with the lowtemperature of the foxtail millet.The results indicated that:(1) When drought stress was maintained at a middle level, all thetreatments of the100mg N·kg-1,150mg N·kg-1,87mg P·kg-1,130.5mgP·kg-1and249mg K·kg-1significantly improved the physiologicalcharacteristics of foxtail millets culturing in sand, the contents ofsoluble sugar and soluble protein as well as the enzyme activity ofPOD, SOD and CAT in the seedling of foxtail millet were apparently increased, and the MDA contents in the seedling of foxtail millet wereremarkably decreased. However, the physiological performance offoxtail millets culturing in sand exhibited better effects when therates of100mg N·kg-1,150mg N·kg-1,87mg P·kg-1,124.5mg K·kg-1and249mg K·kg-1were respectively supplied under heavy drought stress.Our data showed that when the plants were subjected to droughtstress, the supply of abundant nitrogen, phosphorus and potassiumexhibited better reciprocation effects for the foxtail millet growth atseedling stage comparing to the treatment without water supplement.This study suggested that when the mild drought stress wasmaintained, although application of nitrogen, phosphorus andpotassium could promote the foxtail millet growth by enhancing thetolerance of plants to drought stress, the supply ranges of adequatefertilizers were limited, and that excessive fertilizer application willcause physiological damages on the foxtail millet growth.(2) Under mild salt stress of the100mg N·kg-1,87mg P·kg-1,249mgK·kg-1, under moderate salt stress of the100mg N·kg-1,43.5mg P·kg-1,and124.5or249mg K·kg-1, under severe salt stress of the100mgN·kg-1,43.5mg P·kg-1, and124.5mg K·kg-1significantly improved thephysiological characteristics of foxtail millets culturing in sand, thecontents of soluble sugar and soluble protein as well as the enzymeactivity of POD, SOD and CAT in the seedling of foxtail millet wereapparently increased, and the MDA contents in the seedling of foxtailmillet were remarkably decreased. This study suggested that NPKinteraction application could promote the foxtail millet growth byenhancing the tolerance of plants to salt stress. Under salt conditions,although NPK fertilizer can promote the growth and increase resistance of millet, but the range of NPK fertilizer smaller, morefertilizer could cause salt. Pand K was more suitable for improving thesalt resistance of millet seedlings, the excess N, P, K are not suitable.(3)Under low temperature was maintained at a middle level, all thetreatments of the100mg N·kg-1,87mg P·kg-1,130.5mg P·kg-1,249mgK·kg-1and373.5mg K·kg-1significantly improved the physiologicalcharacteristics of foxtail millets culturing in sand, the contents ofsoluble sugar and soluble protein as well as the enzyme activity ofPOD and SOD in the seedling of foxtail millet were apparentlyincreased, and the MDA contents in the seedling of foxtail millet wereremarkably decreased. This study suggested that when the coldstress was maintained, although application of nitrogen, phosphorusand potassium could promote the foxtail millet growth by enhancingthe tolerance of plants to cold stress, the supply ranges of adequatefertilizers were limited.