Assessing biologically Degraded Soil : A GIS approach
Satya Priya and Ryosuke Shibasaki
Global Engineering laboratory
Institute of Industrial Sciences, The University of Tokyo
7-22-1, Roppongi, Monato-ku, Tokyo 106, Japan
Fax : 81-3-3479-2762
E-mail :satya@shunji.iis.u-tokyo.ac.jp
Abstract
It is practically impossible for man to produce stable humus synthetically. Man can only properly cultivate the field, supply organic matter and encourage the development of stable humus in the soil. Soil with stable humus must always be protected to maintain the fertility and productivity. Stable humus is the crucial center, the focus of the soil life cycle. Adhering to farming practices that assure the production of stable humus becomes the farmer's main objective. In this paper, the authors discuss the various steps involved in assessing the biological state of the soil, by calculating humus content.
1. Introduction
For nearly one hundred years soil science in most schools of higher learning especially in agricultural sciences has been primarily concerned with the physical and mechanical aspects of soil structure. Biological thinking or biologically degraded soil has become a major concern only in last few years. The new approach consider not only the physical properties and mineral structure of the soil, but also the process by which organic matter is transformed into humus by microorganisms. Good soil consists of 90% mineral and 10% bio-organic substances. The bio-organic parts consists of 70-90% humus, 10-30% roots, and active fraction, which constitutes living organisms and other, constitutes as shown in Figure 1.
Figure 1: Composition of Organic Matter (Source, E. G. Gregorich et al.; 1995)
Some of the nutrients get lost through leaching due to continually wet weather, melting snow, flooding or through denitrification. Also each cultivated plant takes away nutrients from the soil, as soon as the crops are harvested. The substantial task for the farmer is to take care in returning nutrients taken from the soil through harvesting. The conventional farmer is uses water soluble, mostly salty chemical fertilizer. In contrast, the bio-organic farmer uses organic matter in the form of crop residues, and other wastes, and/or compost, in order to take of soil life, its proliferation and simulation to highest effectively. Microbial soil compound plays one of the most important roles in the decomposition of organic litter. Soil organic matter includes plant and animal remains in various stages of decomposition, cells and tissues of soil organisms, and substances produced by the soil microbes. Well- decomposed organic matter forms humus-a dark brown, porous, spongy material with a pleasant, earthy smell. The occurrence of microorganisms in the soil depends on many factors e.g. on soil acidity, air and soil humidity, air and soil temperature, soil water, all meteorological factors etc.
Seeing an importance of soil biology this study only considers the mineralization of organic matter without erosion. A distinction is made between non-resistant organic matter (i.e. fresh organic residues) and resistant organic matter (humus). The biological degradation dealt in this study is as mineralization of resistant organic matter mainly based and soil parameter, which calculates the decay rate of humus.
2. Study Area
The chosen study are in this study is India, lies to the north of equator, between 8o4' and 37o6' North and 68o7' and 97o25'. East It is bounded in the south by the Indian Ocean, in the west by the Arabian Sea, in the east by Bay of Bengal, in the north-east, north and a part of the north-west by Himalayan ranges, and the rest of the north-west by the Great Indian Desert.
Physiographically, India can be divided into seven regions: the Northern Mountains, constituting the Himalayan ranges; the great Indo-Ganagetic Plain; the Central Highlands; the peninsular Plateau in the states of maharashtra, Andhara pradesh, Karnataka and Tamil nadu; the East Coast; the West Coast; and the Island. The average elevation of the plateau that dominates most of Peninsular India ranges between 300 and 1800 m. The river systems of India may be broadly classified into two groups: the Himalayana and the Deccan. The main rivers of the Himalayan group, which are snow-fed, are the Indus, Ganga and Brahmaputra including their major of the country. The Deccan system include the west-flowing Narmada, Tapi and Periyar and the east-flowing mahandi, Godavari, Krishna, Penneru and kaveri.
The Republic of India's mainland stretches 3214 kms from north to south and 2933 kms from west to east. The total land area is 3.29 million sq. kms. Size wise it is the sixth largest country in the world. India exhibits a variety of landscapes and climatic conditions in the evolution of different soils and vegetation. It shows a string relationship among the soils, climate and vegetation.
