Hani rice terraces system is one of the Globaly Important Agricultural Heritage Systems （GIAHS） pilot sites selected by FAO. Soil nutrients are an important symbol of soil fertility, and play an important role in th...Hani rice terraces system is one of the Globaly Important Agricultural Heritage Systems （GIAHS） pilot sites selected by FAO. Soil nutrients are an important symbol of soil fertility, and play an important role in the sustainable utilization of land. Based on geo-statistics and GIS, the spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen, available phosphorus and available potassium in the soil in Yisa （a town in Honghe County, Yunnan Province） was studied. The results show that the spatial variability of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium exhibited medium spatial variability, and the coefficients of variation are 12.54%, 40.14%, 40.00%, 34.89%, and 40.00% respectively. Available phosphorus exhibited strong spatial variability, and the coefifcient of variation is 102.13%. The spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium fit the index mode, however, the spatial variation of available phosphorus ifts the spherical model. Total nitrogen, available phosphorus and available potassium were greatly affected by soil structural factors, while pH, organic matter and alkaline hydrolyzable nitrogen were affected by both structural and random factors. The spatial distribution of soil nutrients in Yisa was intuitively characterized by Kriging interpolation. It is very important to understand the spatial distribution of soil nutrients, which wil provide the guidance for adjusting agricultural management measures such as fertilization.展开更多
Total nitrogen(TN),total phosphorus(TP),total potassium(TK),and soil organic matter(OM)can significantly affect forest growth.However,these soil properties are spatially heterogeneously distributed,complicating the pr...Total nitrogen(TN),total phosphorus(TP),total potassium(TK),and soil organic matter(OM)can significantly affect forest growth.However,these soil properties are spatially heterogeneously distributed,complicating the prescription of forest management strategies.Thus,it is imperative to obtain an in-depth understanding of the spatial distribution of soil properties.In this study,soils were sampled at 181 locations in the Tropical Forest Research Center in the southwestern Guangxi Zhuang Autonomous Region in southern China.We investigated the spatial variability of soil OM,TN,TP,and TK using geostatistical analysis.The nugget to sill ratio indicated a strong spatial dependence of soil TN and a moderate spatial dependence of soil OM,TP,and TK,suggesting that TN was primarily controlled by intrinsic factors(e.g.,soil texture,parent material,vegetation type,and topography),whereas soil OM,TP,and TK were controlled by intrinsic and extrinsic factors(e.g.,cultivation practices,fertilization,and planting systems).Based on the spatial variability determined by the geostatistical analysis,we performed ordinary kriging to create thematic maps of soil TN,TP,TK,and OM.Model validation indicated that the thematic maps were reliable to inform forest management.展开更多
Soil salinization is a type of soil degradation phenomenon caused by the gradual accumulation of salt in soil due to natural processes or improper irrigation practices.Understanding the spatial variations of salinizat...Soil salinization is a type of soil degradation phenomenon caused by the gradual accumulation of salt in soil due to natural processes or improper irrigation practices.Understanding the spatial variations of salinization is the basis for salinized land management and resource utilization.Taking Yinbei Plain irrigation area of Ningxia as the research area,154 sampling points were set up and soil samples were collected at depths from 0-100 cm in six layers to determine the pH value and total salt content of the soil.Then geostatistics and GIS were used to study the spatial variations of soil pH and total salt content in the irrigation area.The results show three important aspects of this system.(1)The soil in the study area is alkaline soil with pH values ranging from 8.18 to 10.22,and the pH increases with increasing soil depth.The pH values of soil at 0-10 cm are significantly higher than at depths of 10-20 cm and 20-80 cm(P<0.05).The variation coefficients of the soil pH value in each layer are less than 10%,which is characterized as weak variability.The total salt content of soil decreases with increasing soil depth,ranging from 0.24 to 14.95 g kg^(-1).The total salt content of soil in the surface layer at 0-10 cm was significantly higher than in the lower soil layers(P<0.05).The coefficient of variation of total salt content showed moderate variability except at depths of 10-20 cm and 80-100 cm.Other layers have variabilities of more than 100%,indicating strong variability.(2)The semi-variance function fitting of pH and total salt showed that the soil pH value in each soil layer depth block base ratio ranged from 28.1%to 61.2%,which indicates a medium spatial correlation,and the spatial variability was mainly influenced by the joint action of human activities and natural factors.The total salt block base ratio of each soil layer ranged from 5.5%to 13.3%,which indicates strong spatial autocorrelation.The variation among soil samples is mainly caused by natural structural factors such as parent material,topography,soil and groundwater level.(3)Kriging interpolation was used to obtain the spatial distribution of soil pH values and total salt contents in the study area,and the results showed that the overall pH distribution was high on the eastern and western sides and low in the middle.The total salt distribution was patchy and uneven,and the saline soil was mainly distributed in the surface layer.As the depth increased,the total salt content declined,and the proportions of saline soil and severely salinized soil decreased.In the whole study area,mild salinized soil was the main category,the total salt content increased from south to north,and the profile characteristics of total salt content were mainly surface clustering.This study investigated the distribution and spatial heterogeneity of soil salinization in the Yinbei Irrigation Area,and provides theoretical guidance for the formulation of soil salinization control measures in this area.展开更多
基金National Natural Science Fund of China(31200376)
文摘Hani rice terraces system is one of the Globaly Important Agricultural Heritage Systems （GIAHS） pilot sites selected by FAO. Soil nutrients are an important symbol of soil fertility, and play an important role in the sustainable utilization of land. Based on geo-statistics and GIS, the spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen, available phosphorus and available potassium in the soil in Yisa （a town in Honghe County, Yunnan Province） was studied. The results show that the spatial variability of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium exhibited medium spatial variability, and the coefficients of variation are 12.54%, 40.14%, 40.00%, 34.89%, and 40.00% respectively. Available phosphorus exhibited strong spatial variability, and the coefifcient of variation is 102.13%. The spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium fit the index mode, however, the spatial variation of available phosphorus ifts the spherical model. Total nitrogen, available phosphorus and available potassium were greatly affected by soil structural factors, while pH, organic matter and alkaline hydrolyzable nitrogen were affected by both structural and random factors. The spatial distribution of soil nutrients in Yisa was intuitively characterized by Kriging interpolation. It is very important to understand the spatial distribution of soil nutrients, which wil provide the guidance for adjusting agricultural management measures such as fertilization.
基金The National Key Research&Development Program of China(2016YFD060020501).
文摘Total nitrogen(TN),total phosphorus(TP),total potassium(TK),and soil organic matter(OM)can significantly affect forest growth.However,these soil properties are spatially heterogeneously distributed,complicating the prescription of forest management strategies.Thus,it is imperative to obtain an in-depth understanding of the spatial distribution of soil properties.In this study,soils were sampled at 181 locations in the Tropical Forest Research Center in the southwestern Guangxi Zhuang Autonomous Region in southern China.We investigated the spatial variability of soil OM,TN,TP,and TK using geostatistical analysis.The nugget to sill ratio indicated a strong spatial dependence of soil TN and a moderate spatial dependence of soil OM,TP,and TK,suggesting that TN was primarily controlled by intrinsic factors(e.g.,soil texture,parent material,vegetation type,and topography),whereas soil OM,TP,and TK were controlled by intrinsic and extrinsic factors(e.g.,cultivation practices,fertilization,and planting systems).Based on the spatial variability determined by the geostatistical analysis,we performed ordinary kriging to create thematic maps of soil TN,TP,TK,and OM.Model validation indicated that the thematic maps were reliable to inform forest management.
基金The Key Research and Development Program of Ningxia Hui Autonomous Region(2022BEG03053)The National Key Research and Development Program of China(2921YFD1900600)The Innovation and Entrepreneurship Project for Returned Overseas Talents in Ningxia Hui Autonomous Region(Ningxia Human Resources and Social Security Office Notice No.5,2023)。
文摘Soil salinization is a type of soil degradation phenomenon caused by the gradual accumulation of salt in soil due to natural processes or improper irrigation practices.Understanding the spatial variations of salinization is the basis for salinized land management and resource utilization.Taking Yinbei Plain irrigation area of Ningxia as the research area,154 sampling points were set up and soil samples were collected at depths from 0-100 cm in six layers to determine the pH value and total salt content of the soil.Then geostatistics and GIS were used to study the spatial variations of soil pH and total salt content in the irrigation area.The results show three important aspects of this system.(1)The soil in the study area is alkaline soil with pH values ranging from 8.18 to 10.22,and the pH increases with increasing soil depth.The pH values of soil at 0-10 cm are significantly higher than at depths of 10-20 cm and 20-80 cm(P<0.05).The variation coefficients of the soil pH value in each layer are less than 10%,which is characterized as weak variability.The total salt content of soil decreases with increasing soil depth,ranging from 0.24 to 14.95 g kg^(-1).The total salt content of soil in the surface layer at 0-10 cm was significantly higher than in the lower soil layers(P<0.05).The coefficient of variation of total salt content showed moderate variability except at depths of 10-20 cm and 80-100 cm.Other layers have variabilities of more than 100%,indicating strong variability.(2)The semi-variance function fitting of pH and total salt showed that the soil pH value in each soil layer depth block base ratio ranged from 28.1%to 61.2%,which indicates a medium spatial correlation,and the spatial variability was mainly influenced by the joint action of human activities and natural factors.The total salt block base ratio of each soil layer ranged from 5.5%to 13.3%,which indicates strong spatial autocorrelation.The variation among soil samples is mainly caused by natural structural factors such as parent material,topography,soil and groundwater level.(3)Kriging interpolation was used to obtain the spatial distribution of soil pH values and total salt contents in the study area,and the results showed that the overall pH distribution was high on the eastern and western sides and low in the middle.The total salt distribution was patchy and uneven,and the saline soil was mainly distributed in the surface layer.As the depth increased,the total salt content declined,and the proportions of saline soil and severely salinized soil decreased.In the whole study area,mild salinized soil was the main category,the total salt content increased from south to north,and the profile characteristics of total salt content were mainly surface clustering.This study investigated the distribution and spatial heterogeneity of soil salinization in the Yinbei Irrigation Area,and provides theoretical guidance for the formulation of soil salinization control measures in this area.
