| With population growth and economic development,people’s demand for food production was increasing,so the pressure on agricultural soil resources was increasing.The average annual fertilizer application in China was almost three times the world level,but the efficiency of nitrogen fertilizer utilization was far less than that of other countries.The irrational application of fertilizers leads to a series of environmental problems,such as soil acidification,increased greenhouse gas emissions and eutrophication,which threaten the sustainable development of agriculture.The effect of fertilizers on soil properties is uncertain due to specific geography,fertilization types,crop types and soil textures.Therefore,this study investigated the patterns of fertilizer application on soil chemical properties under the influence of natural factors（climatic conditions,soil texture）and anthropogenic activities（fertilizer types,fertilization duration,crop types）using Meta-analysis method based on 2058data sets published from 1990 to 2020.The potential relationship between soil chemical properties and the effect of fertilizer on soil carbon fixation under the conditions of climate and crop are discussed in depth.A large field experiment was conducted at the Aksu Oasis Farmland National Field Experiment Station in Xinjiang from 2018-2022 to study the effects of different water and fertilizer management on soil chemical properties,crop yield,and nitrogen and irrigation water use efficiency.This study can provide scientific guidance and theoretical basis for sustainable agricultural soil field fertilization management.The main research conclusions are as follows:（1）Compared to the unfertilized control（CK）,the application of nitrogen,phosphorus and potassium plus manure（NPKM）to agricultural soils in China resulted in the greatest increase in soil chemical properties（soil organic carbon（SOC）（67%）,total nitrogen（TN）（63%）,alkali-hydrolysable nitrogen（AN）（70%）,total phosphorus（TP）（149%）and available potassium（AK）（281%））,and alleviated the acidification trend of the soil（ΔpH:-0.1）.However,the increase in nitrogen fertilizer（N）alone was the lowest,with pH decreasing by0.6 units.With the growth of fertilization time,the content of SOC and TN increases faster under the influence of organic fertilizer（manure or straw）.The increase of SOC,TN,AN and AK in all fertilization management was the lowest in the humid area.The increase of SOC（+115%）and TN（+84%）was the highest after NPKM in arid areas,In addition,the increase in soil chemical properties was higher in unflooded crops.Fertilizer had a more rapid effect on the change of organic carbon and total nitrogen in sandy loam soils compared to the control group.Compared to the control,fertilizers produced faster effects on the change in the SOC in sandy loam,with the maximum value occurring in the 19th year of fertilization.Fertilizers showed the highest and lowest effects on change in pH,organic C to total N ratio（C/N）,TP and TK in clay loam with the cultivation duration.（2）The application of NPKM resulted in the highest increase in soil pH,SOC and TN in areas outside of China,and the smallest increase in N fertilizer alone.However,single application of nitrogen fertilizer made China’s farmland soil acidification more serious（the decline rate of pH was 0.37 units lower than that of China’s farmland soil）.Soil pH was 0.46and 0.18 units higher after application of organic fertilizer（NPK+manure/straw）than that of Chinese farmland soils.Fertilizer application in arid areas in other parts of the world is beneficial to increase TN content,especially NPKM increases TN content more than in China.Similarly,fertilization in sandy loam soils with low precipitation and temperature can rapidly increase SOC and TN content,with a maximum value in the second year.（3）The Boosted regression tree analysis showed that anthropogenic factors,especially fertilization,were more important for the observed changes in soil chemical properties.Compared with NPK fertilizer,NPKM increased soil C/N by 1.74 times in arid areas and 1.86times in wheat crop conditions.Minimal addition of N in wheat growing areas and low levels of phosphorus and potassium in rice growing areas can effectively increase soil carbon stocks.There is a maximum threshold range of total N content in the soil for crop yield increase(maize:0.5-1.5 g kg-1,wheat:0.5-1.2 g kg-1,rice:1.8-3.5 g kg-1),and excessive fertilization does not guarantee a sustained yield increase.（4）After 5 years of fertilizer+straw return treatment,the soil total carbon and total nitrogen contents were significantly increased.Compared with the control,the content of total carbon（TC+7.8%）and total nitrogen（TN:+170%）in 0-5cm soil profile increased the highest in 2022 when high water and fertilizer+straw returned to the field.The changes of TC and TN under the same water and fertilizer treatments were different during the growth of maize.TC content in soil profile 0-5 cm was highest in 2022 after HNHW+straw return application at corn filling stage(35.3 g kg-1)and TN content was highest at corn pulling stage with HNHW+straw return application(1.33 g kg-1).TN content after application of MNHW with straw return at the 2019-2020 corn tassel stage was higher than that after application of HNHW with straw return.Thus,the maximum TN content cannot be determined by HNHW+straw returning to the field,while MNMW+straw returning to the field can also ensure the soil nitrogen content at different periods.（5）Although the HNHW+straw return measure was effective in increasing corn yield,the MNMW+straw return management had the highest nitrogen use efficiency and irrigation water use efficiency.Therefore,MNMW+straw returning to the field are the most suitable field fertilization and irrigation water management mode in the arid region.The treatment of returning fertilizer and straw to the field can effectively increase Soil carbon stock,improve soil fertility and increase crop yield,which is a win-win agricultural development strategy beneficial to the environment. |
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