STUDIES ON SITE SPECIFIC NUTRIENT MANAGEMENT (SSNM) USING GEOSPATIAL TECHNIQUES IN CHINNAPALEM VILLAGE OF GUNTUR DISTRICT
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Date
2022-08-12
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guntur
Abstract
The texture of the surface soils varied from sandy clay loam to clay. While, in sub-surface clay and colour was varied from dark grayish to black. The bulk density values of the soils were low at surface compared to sub-surface layers. Water holding capacity and volume expansion values varied according to clay content.
Soil pH was neutral to moderately alkaline while sub-surface was more alkaline than surface. Surface and sub-surface soil samples of the study area were found to be normal in soluble salt concentration.
The surface and sub-surface soil samples were low to high in organic carbon content. The available nitrogen content was low to medium in surface and sub-surface. The available P2O5 content was medium to high in surface and low to high sub-surface soils. The available K2O content of the soils varied from medium to high in both surface and sub-surface soil samples.
The available calcium and magnesium contents were well above the critical limits at surface and sub-surface. Contents of available calcium and magnesium were more in sub-surface than surface soils. The soils were low to medium in available sulphur content which was higher in the surface soils.
The soils of study area were sufficiently rich in Zn, Fe, Mn and Cu but some part of area were deficient in zinc and iron. All macro and micronutrients were significantly and positively correlated with organic carbon as it was the predominant factor, which controled availability of nutrients in soils.
Spatial variability of soil properties was studied and maps were generated based on the data generated using geo-statistics. In the present study, the variability was observed in the availability of all the nutrients except calcium, magnesium, and copper at both surface and sub-surface soil samples.
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The site specific fertilizer recommendations for Rice, Maize and Sorghum for both surface and sub-surface levels in Chinnapalem village were developed utilizing the thematic maps of spatial variability of N, P and K status. A delineated variable rate of fertilization maps for NPK based on STCR to targeted yields of rice, maize and sorghum revealed that the corresponding recommendation and application of fertilizers was essential to improve the efficacy of fertilizer application and enhancing the returns to the growers.
The hyperspectral data revealed that soil reaction, available Mg, Zn, Fe, Cu and Mn showed positive and significant correlation. However, EC and available S were negative and significant throughout visible and SWIR. From, Stepwise regression approach the poorest fit was observed in all the properties although the highest accuracy (R2=0.467) was found for available zinc, while lowest predictability (R2=0.028) was for sand.
It can be summarized that geospatial techniques are highly reliable in generating natural resource database to integrate and assess their potential on spatial basis. The use of geostatistics enabled the assessment of heterogeneous nature of fertility variations. Integration of GIS with various models in the present study was highly useful in correlation studies between spectral indices and soil properties, generating the soil fertility and fertilizer recommendation maps and management of crop fields provided the real time availability of high spatial resolution satellite data is ready available.
Description
STUDIES ON SITE SPECIFIC NUTRIENT MANAGEMENT (SSNM) USING GEOSPATIAL TECHNIQUES IN CHINNAPALEM VILLAGE OF GUNTUR DISTRICT