Stretching Soil Sampling to Watershed: Evaluation of Soil‐Test Parameters in a Semi‐arid Tropical Watershed

Sahrawat, K L and Rego, T J and Wani, S P and Pardhasaradhi, G (2008) Stretching Soil Sampling to Watershed: Evaluation of Soil‐Test Parameters in a Semi‐arid Tropical Watershed. Communications in Soil Science and Plant Analysis, 39 (19-20). pp. 2950-2960. ISSN 0010-3624

PDF - Published Version
Download (501kB) | Preview


Soil sampling is an integral component of fertility evaluation and nutrient recommendation for efficient use of nutrients in crop production. Little attention has been devoted to evaluating methodology for sampling watersheds under dryland agriculture. A stratified random sampling methodology for sampling the Appayapally watershed in Mahabubnagar district of Andhra Pradesh state in the semi‐arid tropical region of India was adopted and evaluated. The watershed has an area of about 500 ha, with gentle sloping lands (<1% slope), and 217 farmers own land in the watershed. The soils are Alfisols. A total of 114 soil samples were collected from the top 15‐cm layer to represent the entire watershed. Each sample was a composite of 7–8 cores, randomly collected from the area represented by a crop and group of farmers. The soil samples were air dried, ground, and analyzed for pH, electrical conductivity (EC), organic carbon (C), total nitrogen (N), and extractable phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), sulfur (S), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), and boron (B). Statistical analysis of the results on soil fertility parameters showed that the mean‐ or median‐based results of soil tests performed in the study did not differ significantly when the sample set size varied from 5 to 114 (100% of the population). Our results indicate that farmers' fields in the Appayapally watershed are uniform in the chemical fertility parameters studied, and even a small sample set size can represent the whole population. However, such a sampling strategy may be applicable only to watersheds that are very gently sloping and where fertilizer use is very low, resulting in an overall low fertility in the whole watershed.

Item Type: Article
Uncontrolled Keywords: Dryland agriculture, low chemical fertility, semi-arid region, soil sampling in watersheds, spatial variability in soil tests, stratified random sampling
Subjects: Others > Soil Science
Others > Watershed Management
Depositing User: Mr Sanat Kumar Behera
Date Deposited: 13 Oct 2011 11:56
Last Modified: 13 Oct 2011 11:56
Official URL:
Funders: Government of Andhra Pradesh-APRLP, Department for International Development
Acknowledgement: We thank the Andhra Pradesh Rural Livelihood Program (APRLP) of the Government of Andhra Pradesh and the Department for International Development (DFID) for financial support. We also appreciate the assistance of Mr. S. P. Tucker, the then–project coordinator, and Ms. T. K. Sreedevi, the then–additional project coordinator APRLP in implementation of the watershed program under which the nutrient management trials were conducted. We are thankful to Dr. Subhash Chandra and Mr. V. P. Prasanth of the ICRISAT Statistics unit for their assistance in statistical analysis of the data.
View Statistics

Actions (login required)

View Item View Item