[1]Song Shujun,Cui Xiaoru,Chen Xiong,et al.Effects of Fallow on Soil Nutrients in the Dryland Farming Area of Central Gansu[J].Research of Soil and Water Conservation,2023,30(06):143-150,159.[doi:10.13869/j.cnki.rswc.2023.06.013]
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
30
Number of periods:
2023 06
Page number:
143-150,159
Column:
Public date:
2023-10-10
- Title:
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Effects of Fallow on Soil Nutrients in the Dryland Farming Area of Central Gansu
- Author(s):
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Song Shujun1,2, Cui Xiaoru3, Chen Xiong4, Chen Qixian3, Yang Rong1, You Yanrong3
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(1.Linze Inland River Basin Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; 2.University of Chinese Academy of Sciences, Beijing 100049, China; 3.Gansu General Station of Agrotechnology Extension, Lanzhou 730000, China; 4.An'ding District Center of Agricultural Technology Extension in Dingxi City, Dingxi, Gansu 743000, China)
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- Keywords:
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fallow; farmland soil; soil nutrient; cultivated land quality; dryland farming area of central Gansu
- CLC:
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S156; S158.3
- DOI:
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10.13869/j.cnki.rswc.2023.06.013
- Abstract:
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[Objective] The aims of this study are to evaluate the effects of fallow on soil nutrients in farmland, clarify the suitability of fallow patterns, and provide a scientific basis for developing appropriate land management measures and improving the quality of soils in this area. [Methods] Based on the fallow trial data of three consecutive years from 2017 to 2019, seven soil nutrient indexes, including soil organic matter(SOM), total nitrogen(TN), available phosphorus(AP), available potassium(AK), pH value, exchangeable calcium and exchangeable magnesium, were selected to compare the changes in soil nutrients before and after the implementation of the fallow mode of green manure cultivation and the differences in soil nutrients between fallow and non-fallow controls(potato-corn-potato rotation)by using farmland in the dryland farming area of central Gansu as the research object. [Results](1)Compared with the basic nutrients before fallow, the contents of SOM, TN and AK showed the increasing trend after three years of fallow, increasing by 19.5%, 23.0% and 9.2%, respectively, in which there were significant differences(p<0.05)in the contents of SOM and TN before and after fallow, except for AK; AP, pH value, and exchangeable calcium and magnesium significantly decreased by 21.8%, 1.0%, 36.5% and 39.6%, respectively(p<0.05).(2)Compared with the non-fallow control, the contents of SOM, TN and AK were 3.5%, 11.0% and 8.5% higher than those in the control area, respectively. AP and exchangeable calcium were lower than those in the control area. However, there were significant differences only in the contents of TN and exchangeable calcium(p<0.05).(3)There was a significant logarithmic relationship between the rate of change of AP and its basic content(p<0.001), and a significant negative linear function between the rate of change of SOM, TN, AK and pH value and their basic content(p<0.01). In other words, the effect of fallow on change of soil nutrients decreased with the increase of its basic nutrients, but this relationship was not significant for exchangeable calcium and exchangeable magnesium.(4)After three years of fallowing, there were remarkable positive correlations among SOM, TN, AK and AP(r>0.38, p<0.05). The pH value was significantly negatively correlated with other soil nutrient indexes except exchangeable magnesium(p<0.01). The correlation of soil nutrient indexes in the fallow area was higher than that in the control area. [Conclusion] The fallow mode of green manure planting can improve the quality of cultivated land in the dryland farming area of central Gansu to some extent, and it is more effective for soils with low basic nutrients. However, the three-year fallow is less effective than the potato-maize crop-potato rotations, indicating that the improvement effect of fallow on soil is still limited in a relatively short time scale.