Influence Of Traditional And Non-traditional Crop Cultivation Models On Soil,Water And Nutrient Loss In The Karst Areas

Most of the karst areas are characterized by high rock exposure,shallow soil layer,low soil fertility and extremely fragile ecological environment.The ecological environment in Karst area is strongly disturbed by humans,mainly manifested as the disturbance of agricultural activities to the natural environment.In order to improve the natural ecological environment in karst areas、consolidate regional farming cultureand enhance the living quality of local farmers,it is of great theoretical and practical significance to study the relationship between cultivation culture and natural ecological environment in karst areas.In this study,based on ecological balance theory,ecosystem structure theory,sustainable development theory,and man-land relationship theory,the karst plateau in Guizhou,which represents the overall structure of karst ecological environment in southern China,Guanling-Zhenfeng Huajiang middle-strong rocky desertification control demonstration area and Shibing no-potential rocky desertification comprehensive demonstration area are regarded as the research areas.Through questionnaire survey and field monitoring,more than 200 rural households were surveyed in two research areas from 2017 to 2019;and continuous monitoring and data collection from 10 sample plots in two research areas in April,July,and November 2019,and laboratory analysis of 17 indicators of 810 samples.Background of the cultivation area in the study area was the clarified,and the crop cultivation pattern under the traditional and non-traditional cultivation culture in the study area were selected to prove the physical and chemical properties of soil and the situation of soil and water-nutrient loss.Finally,aiming at the research experimental observation results and questionnaire survey,clarify the cultural effect of the current status of soil erosion and nutrient loss,and provide corresponding countermeasures and suggestions on the coordination relationship between the cultivation culture and the natural environment in the demonstration area.The research conclusions are as follows:1.There is an obvious phenomenon of cultural transition in the study area,the agricultural activities under the traditional farming culture interfered with the cultivated land environment significantly higher than the non-traditional farming culture.In traditional farming culture,crops are planted mainly to solve the problem of food and clothing,and focus on economic benefits.Traditional crops are represented by Zea mays,and the treatment of cultivated land is continuous plowing.In order to pursue the comprehensive benefits of ecological environment and social economy,non-traditional crops are mainly regional new cash crops,mostly perennial crops,and the human disturbance during the cultivation activities is relatively weak,the division of farming culture is of great significance to the consolidation and the development of regional farming culture.Compared with the influence of geological background,climatic conditions,soil environment,rocky desertification level,population distribution and other factors,the impact of agricultural activities of cultivation culture on the cultivated land environment is more obvious.2.Different crop cultivation models have different effects on soil physical and chemical properties,compared with the non-traditional crop cultivation model,the traditional crop cultivation model has certain advantages in soil physical and chemical properties.According to the comprehensive evaluation of soil quality,the comprehensive soil quality score of karst mountain-canyon area showed that the non-traditional crops Hwang kumbae+soybean(0.563),Hwang kumbae+Pseudostellaria heterophylla(0.553),Hwang kumbae(0.520)were larger than the traditional crop Zea mays(0.499).The comprehensive soil quality score of karst plateau-canyon area was shown as non-traditional crops Zanthoxylum bungeanum+Sophorae Tonkinensis Radix et Rhizoma(0.648),Zanthoxylum bungeanum+Arachis hypogaea(0.635),Zanthoxylum bungeanum(0.609)is greater than the traditional crop Zea mays(0.541).Compared with the typical crop Zea mays under traditional cultivation culture,the soil physical and chemical environment of crops under non-traditional cultivation culture has certain advantages,It shows that the farmland soil environment under non-traditional farming cultural activities is superior to traditional farming culture.3.The distribution characteristics of nutrients of different crop cultivation patterns in different slope positions are as follows:lower slope>middle slope>upper slope,and the accumulation of nutrients in middle slope and upper slope is more significant,indicating that the characteristics of soil nutrient transport on slope are obvious in karst areas.The soil organic carbon content in lower slope of the traditional crop corn is 2.12 times higher than that in upper slope,and the soil organic carbon content in lower slope of the non-traditional crops pear tree+soybean,pear tree+Pseudostellaria heterophylla and pear tree is1.51,1.91 and 2.34 times higher than that in upper slope,respectively.Compared with non-traditional crops,the difference in nutrients in upper slope and lower slope of traditional crops is more obvious,and the intensity of soil nutrient transport is relatively greater,indicating that traditional crops are more prone to soil and nutrient loss than non-traditional crops.That is,the soil and water conservation effect of non-traditional farming cultural activities is better.The distribution patterns of soil nutrient slopes under different lithologies in Shibing dolomite and Huajiang limestone are similar,indicating that crops and corresponding farmland treatment methods and slopes have a greater impact on surface soil transport characteristics than lithology.4.There are some differences in the degree of influence of different crop cultivation modes on soil erosion and nutrient loss,the loss of soil and water nutrients under the traditional crop cultivation model is more serious than that of non-traditional crop cultivation models,but not all non-traditional crops have absolute advantages in soil and water conservation.The average runoff coefficient of karst mountain-canyon area is that the traditional crop Zea mays(13.98%)is larger than the non-traditional crop Hwang kumbae(11.48%),Hwang kumbae+Pseudostellaria heterophylla(6.26%)and Hwang kumbae+soybean(4.55%);the average sand yield is that the traditional crop Zea mays(32.46 g/m~2)is larger than the non-traditional crop Hwang kumbae(16.68 g/m~2),Hwang kumbae+Pseudostellaria heterophylla(2.64g/m~2)and Hwang kumbae+soybean(2.20 g/m~2).The average runoff coefficient of karst mountain-canyon area is that traditional crop Zea mays(27.28%)is larger than non-traditional crops Zanthoxylum bungeanum(24.45%),Zanthoxylum bungeanum+Sophorae Tonkinensis Radix et Rhizoma(15.26%),Zanthoxylum bungeanum+Arachis hypogaea(13.16%);the average sand yield is that the traditional crop Zea mays(50.04%)is larger than the non-traditional crops Zanthoxylum bungeanum(20.57%),Zanthoxylumbungeanum+Arachis hypogaea(5.35%)and Zanthoxylum bungeanum+Sophorae Tonkinensis Radix et Rhizoma(4.75%).Compared with the traditional crop Zea mays,the loss concentration of each nutrient index of non-traditional crops is relatively small.Not all non-traditional crops have absolute advantages in soil and water-nutrient retention.The non-traditional crops of pear and prickly ash in the two research areas have certain disadvantages compared to the interplanting model.5.There is a coupling effect between natural environment and farming culture in Karst area.The natural status of water and soil-nutrient loss has a certain impact on farmers’environmental awareness,poor natural environment status makes it easier for farmers to be more vigilant in environmental protection.In karst potential rocky desertification grade research area,15%of farmers believe that environmental protection is very important,44%of farmers think it is important,25%of them think it may be important,and 16%of them think it is not important.In middle-strong rocky desertification grade research area,25%of farmers think environmental protection is very important,55%of farmers think it is important,18%of farmers think it may be important,and 2%of farmers think it is not important.Differences in environmental protection awareness indicate that the current situation of harsh natural environment is more likely to increase farmers’vigilance in environmental protection,it helps to update farmers’traditional agricultural concepts,regulate farmland behavior,and promote the improvement and development of farming culture.