Soil Fertility Mapping of Chilli Growing Areas of Taluka Kunri, Sindh, Pakistan

Abstract

Soil fertility evaluation is an important tool for site-specific fertilization for sustainable crop production. Regular monitoring of soil fertility status provides basis for the precious soil resource management. TalukaKunri is the most important chilli growing tract of Pakistan and is the largest chilli market of Asia. However, no any study reports its status of physicochemical properties and fertility of soil. We mapped selected physicochemical properties and nutrient status of talukaKunri, Sindh, Pakistan. A total of 50 soil samples were collected from major chili growing tract of six union councils of talukaKunri, from 0-20 cm depth and their coordinates were recorded. The results revealed that 80% soils were heavy in texture while 20% soils were medium-textured loams. Electrical conductivity (dS m-1) ranged from 0.3-7.2 (avg: 1.6, mode: 1.3). Majority (68%) of soil samples were non-saline (EC: <2.0 dS m-1) followed by very slightly saline (28%) soils (EC: 2-4 dS m-1). SoilpH ranged from 7.7-8.5 (avg: 8.1, mode: 8.2). Most (70%) of the soil samples were medium alkaline in nature (pH: 7.6-8.2) while remaining (30%) were strongly alkaline (pH: 8.3-8.5). Lime content ranged from 0.4-29.4% (avg: 11.9%, mode: 4.8%). Majority of soils were strongly (46%) or moderately (40%) calcareous (CaCO3: >15% and 3-15%, respectively). Organic matter ranged from 0.4-1.17% (avg: 0.8%, mode: 1.04%). No soil sample was found to have adequate (>1.29%) organic matter. The organic matter for 56% soils was found to be deficient (<0.86%) while for 44% soils it was medium (86-1.29%). Soil ABDTPA-P (mg kg-1) ranged from 0.9-7.1 (avg: 3.4, mode: 2.4). Half of the soils had low P content, whereas, 48% soils had medium P content. Only a negligible portion of soils (2%) were found to have adequate P. Soil ABDTPA-K (mg kg-1) ranged from 40-620 (avg: 124.6, mode: 100 mg kg-1). Majority of soil samples (64%) were found to have medium K content while 12% soils had low K content. K content of only 24% soils was found adequate. We recommend site-specific balanced fertilization and use of organic amendments for the soils of chili growing areas of talukaKunri for sustainable chili production.