Soil NPK variability mapping for Harumanis mango grown in greenhouse at Perlis, Malaysia

Abstract

Soil is essential for plant growth. The soil provides support for plant, medium for root growth, and most importantly it offers nutrients for plant uptake. The nutrients variability in soil is vary depending on several factors such as soil type, soil microbes, and soil pH. Therefore, nutrients available in the soil is important to be mapped to investigate the state of nutrient present. In this study, the available content of Nitrogen (N), Phosphorus (P) and Potassium (K) were determined for a high-density planting systems of Harumanis mango plants grown in the greenhouse. Thirty-two soil samples were collected from a greenhouse for analysis of NPK content in top soil. The soil was analyzed using the Kjeldahl method, UV Spectrophotometer and Atomic Absorption Spectroscopy (AAS) for N, P, and K content respectively. These amount of macronutrients were then mapped with respective georeferenced location to produce NPK nutrients maps using standard classification in ArcGIS software. Results have indicated that N, P, and K were ranged between 0.06 - 0.12% (very low), 4 - 648 ppm (low-very high) and 0.02 -1.37 cmol/kg (low-high) accordingly. Overall, it can be concluded, soil in selected greenhouse is poor in N, high in P and moderate in K content. Hence, it is suggested more N and adequate amount of K fertilizer should be supplied to increase the plant's productivity. The produced maps give a new perspective in a farming management concept in term of variable rate fertilizer application for Harumanis mango plants grown in the greenhouse.