Effects Of Different Water And Fertilizer Models On Salinity Control And Yield-increasing Of Coastal Saline Alkali Soil

The effect of integrated control of the shortage of fresh water,the desertification and salinization of soil in the Yellow River Delta area are hard to maintain unsustainable,which have restricted food production and utilization of soil resource in this area.To strengthen the management of water fertilizer,and to investigate improvement effect of different irrigation and fertilization mode on medium saline soil is of great significance for both of the sustainable use of soil resource and he protection of national food security.This study takes “The Bohai Sea barn technological and scientific project” as backing,and makes moderate saline alkali soil wheat-maize wheel as the research object.We set control treatment(CK),custom fertilization(CM),optimized custom fertilization(OCM1,OCM2),chemical fertilization(2/3 basal fertilization + 1/3 top dressing,OM1),organic fertilization(2/3 basal fertilization + 1/3 top dressing,OM2),organic fertilization + reduced chemical fertilization(2/3 basal fertilization +1/3 top dressing(OM3),chemical fertilization(1/3 basal fertilization + 2/3 top dressing,OM4),organic fertilization + chemical fertilization(1/3 top dressing + 2/3 basal fertilization(OM5),organic fertilization + reduced chemical fertilization(1/3 top dressing +2/3 basal fertilization(OM6),we also set OM7、OM8、OM9 treatment to increase irrigation that correspond to OM4、OM5、OM6 treatment to study the effects of salt control and production increase under different irrigation and fertilization mode(fertilization + irrigation)(1)In the wheat season,compared with CK,CM treatment,both of organic fertilizer and chemical fertilizer have the effects of salt control and soil nutrients improvement.Among them,water soluble salt content is lowest under irrigation 2.5 times SPV +organic fertilizer+top dressing: chemical fertilizer(1:2)mode in the mature period,which reduced by 12.6%compared with CK.Under the same fertilization treatment,increasing irrigation amount could reduce 11.5%-12.6% total salt content in 0-20 cm soil,and 7.8%-9.5% total salt content in 20-40 cm soil,meaning that water and fertilization management is the most effective.(2)From the component factor of wheat yield,irrigation and fertilization mode is 2.5 times higher than SPV+organic fertilizer 3600kg/hm2.When the ratio of basal fertilization to top dressing is 1:2 under chemical fertilization(N-P2O5-K2 O =15%-5%-5%),wheat yield was the highest(5384.4kg/ hm2),which increased by 85.2%(wheat yield 2908.05kg/ hm-2)compared with 1.5 times SPV,base fertilization of diammonium phosphate(N-P2O5-K2O=18%-46%)750kg/ hm 2.It is the most optimal irrigation and fertilization mode in this study.(3)In the mature period of Maize,compared with CK,CM treatment,the application of organic fertilizer+2.5 times SPV irrigation treatment has the effect of reducing soil water soluble salt.Among them,The total salt content of one-time topdressing fertilization(N-P2O5-K2 O =15%-5%-5%)in OM4 and OM5 treatments were significantly lower than other treatments,and reduced by 29.2%,32.1% compared with CK,respectively.In the respect of nutrient,both of organic fertilization and chemical fertilization treatment increased soil available nutrients.the soil available phosphorus content of OM5 treatment was highest,which have a significantly trend compared with OM4 treatment(increased by 42.4%).The soil organic matter content of OM5 treatment was higher than that of OM2 treatment by 7.2%.So it is optimum processing mode.(4)In terms of corn yield factors,the yields of all the irrigation and fertilization mode were significantly higher than CK treatment,ranging from 38.66% to 65.43%.Under Early organic fertilizer + 2.5 times the SPV irrigation treatment,the maize yield under one-time topdressing chemical fertilizer 80% F1 OM6 treatment is the highest,which reach to 5184.75kg/ hm2,and increased by 23.14% compared with custom fertilization mode.Results suggest that reducing chemical fertilizer could not decrease Maize yield.(5)The mode of 2.5 times irrigation SPV + organic fertilizer 3600 kg/hm2 + chemical fertilizer(N-P2O5-K2 O = 15%-5%-5%)+ basal fertilization(1:2)can be used as recommended irrigation and fertilization mode to control salt,supply fertilizer,and increase and stabilize yield in the local wheat-maize rotation.