Development of DRIS based soil fertility and leaf nutrient standards for improving the efficiency of Kinnow mandarin (Citrus reticulata Blanco) in semi-arid region of Rajasthan

Abstract

The study was carried out during 2015-16 at district Sriganganagar under semi arid region of Rajasthan India with the aim to diagnose the soil fertility indicator by using DRIS norms to improve the kinnow orchards efficiency. A total 105 kinnow mandarin orchards were selected through the preliminary survey, all the selected orchards were divided equally 35 each in low, medium and high efficiency based on the yield. The soil and plant sample were collected from the orchards and subjected to analyze by using standard analysis protocols. Five tier DRIS norms were used for determining the soil properties limiting factor. The high efficient orchards had low pH (8.1) and CaCO3, (23.4 g kg-1) whereas, comparatively more organic carbon (2.7 g kg-1) , phosphorus (38.2 kg ha-1) and potassium (296.2 kg ha-1) than medium and low efficient orchards. The nitrogen, phosphorus and potassium contents were also high in high yield orchards and ultimately responsible for the better quality parameters viz. fruit weight (170.35 g), Juice (49.51 %), total soluble sugar (12.88 %) and low acidity (0.81 %) in high efficient orchards. The five tier DRIS norms suggested that < 8.8 pH, < 89.0 g kg-1 CaCO3, < 2.5 g kg-1 organic carbon and 14.2 kg ha-1 phosphorus were limiting soil fertility indicators in relation to fruit yield less than 14.5 t ha-1 for kinnow mandarin orchards of semi arid region of Rajasthan. It is evident from the DRIS norms in relation to soil properties and plant tissue concentration yield should be considered as low when it is less than 14.5 to 20.2 t ha-1. It is therefore imperative to manage these parameters for the better quality production and sustainability of kinnow orchards.