Soil Management: An Overview

Abstract

The term “soil management” refers to the human manipulation of chemical, physical, and biological conditions of the soil for the production of agricultural plants. Good soil management helps maintain and improve soil fertility while sustaining optimum crop yield over time, whereas inappropriate soil management practices can lead to the degradation of soil fertility and a declining crop yield within a relatively short period of time. In a cropped field, where pests and disease are not limiting factors, the decline in crop yield over time may be attributed to several soil-related factors, namely, deterioration of soil physical conditions, such as surface crusting and subsurface compaction, depletion of available nutrients in the soil and soil acidification, soil moisture stress (drought or waterlogging), and the decline in soil organic matter and soil biological activity. Thus, major tasks of soil management for crop production include the following: • tillage and seedbed preparation • replenishment of soil nutrients • soil moisture management • maintenance of soil organic matter The main purposes of tillage are to loosen a compacted surface soil to facilitate seed emergence and root growth through improved soil aeration and water storage, and to eradicate weeds before planting and control subsequent weed growth during the cropping season. Common tillage practices used in tropical agriculture are as follows: • Slash-and-burn, followed by sowing seeds into holes made by punching a wooden stick into the porous surface soil. • Slash-and-burn, followed by heaping or ridging the compacted surface soil using a hand hoe. • Plowing, harrowing, and puddling in irrigated rice paddies using water buffalo or a two-wheel power-tiller. • Ridge tillage using a hand hoe, animal traction or an engine-powered tractor on crusted or compacted soils and poorly drained clayey soils. • Minimum or strip tillage with a crop-residue mulch on coarse-textured soils and on sloping land. • Conventional tillage involving plowing and harrowing on fine-textured soils and compacted soils on flatland. • Minimum tillage with a plant-residue mulch or cover crop in annual and tree crop mixed systems (agroforestry).