Effects Of Drip Fertigation On Yield,Nutrient And Water Productivity And Root Distribution Of Spring Maize

Maize growth in Northeast China is suffering from climate change(seasonal drought,cold springs)and low nutrient use efficiency caused by farmer's one-time fertilization habits.Drip fertilization is an effective measure to solve the high efficient use of water and nutrients,and is widely used in vegetable and fruit plant production,yet an efficient and practicable,cost-effective drip fertigation system is lacking for maize production.A four-year and a two-year field experiment was conducted to evaluate the potential of different drip fertigation methods for increasing maize yield,and water and nutrient use efficiency in sandy and clay soil.Five irrigation methods were applied in each soil:conventional(rain-fed,CK),drip irrigation(DI),surface drip fertigation(SDF),fertigation plus plastic film mulching(SDFP),and subsurface fertigation(SSDF).At the same time,a test of two nitrogen levels(N240 and N180)was set up on sandy soil,and the effect of drip fertigation with nitrogen fertilizer(DF-N)and drip fertigation with N,P,and K fertilizers(DF-NPK)was compared with rain-fed(control).The following lists the results from this research:(1)In sandy soil,water optimization management(DI)did not increase maize yield in wet years compared with rain-fed(CK).During the drought years,DI significantly increased the amount of NPK accumulation,dry matter accumulation,fertilizer productivity and yield of maize,but no significant improvement in water productivity.In both wet and dry years,drip fertilization(SDF,SSDF and SDFP)significantly increased maize yield,fertilizer productivity and water productivity.(2)Yield increase rate in sandy soil(DI:20%-38%and SDF:31%-53%)was higher than in the clay soil(DI:8%-16%and SDF:11%-24%).On the basis of drip irrigation water optimization(DI),further optimization of nutrients(SDF)can increase maize yield by 9%-11%and 3%-7%in sandy soil and clay soil,respectively.(3)There was no significant difference in dry matter accumulation,yield and PFP between SDF,SSDF and SDFP methods in both soils.(4)In sandy soil,drip fertigation with N,P and K fertilizer significantly promoted the uptake of phosphorus,dry matter accumulation,yield,nitrogen partial productivity,nitrogen recovery and water productivity compared with drip fertigation with nitrogen fertilizer.(5)In sandy soil,the net profit of DI,SDF,SSDF and SDFP was 13%,28%,31%and 10%higher than that of CK,respectively.In clay soil,however,no o'bvious advantage in net income was found in either DI or fertigation treatments.(6)Drip fertilization significantly increased the total root dry weight and root length density of maize,and mainly increased the root length of fine root(L<0.5mm)at soil depth of 0-20cm.In the wide-narrow row planting mode,drip fertilization increased the root length density on narrow rows of maize.In summary,SDF and SSDF are recommended to increase maize yield,water and nutrient use efficiency,as well as economic benefit synchronously in sandy soil.It is not recommended to use drip irrigation and drip fertigatiopn on clay soil.