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SOIL AND WATER
CONSERVATION RESEARCH IN INDIA
V. V. DHRUVA NARAYANA Central Soil and Water Conservation Research and Training Institute Dehradun
HI<P3M!r ICAR
Published by
Directorate of Information and Publications of Agriculture
Indian Council of Agricultural Research
r
Krishi Anusandhan Bhavan, Pusa New Delhi-110012
First Printed Reprinted Reprinted
December 1993 April 2002 August 2012
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DR D K AGARWAL
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AH Rights Reserved Š2012, Indian Council of Agricultural Research New Delhi
Price : Rs 300.00
Published by Dr D.K. Agarwal, Project Director, Directorate of Knowledge Management in Agriculture, Indian Council of Agricultural Research, Krishi Anusandhan Bhavan, Pusa, New Delhi and Printed at M/s Chandu Press, D-97, Shakarpur, Delhi-110092
CONTENTS Page
1. 2.
3. 4.
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.
'1
Preface Introduction Soil Erosion Factors Affecting Erosion Estimation of Soil Loss Land-Capability Classification Soil and Water Conservation in India - An Overview Mechanical Measures Water Harvesting, Recycling and Estimation of Runoff Agronomic Measures in Soil and Water Conservation Conservation Forestry Grassland Development Horticulture Agroforestry Regional Problems of Soil and Water Conservation
Ravines Hydrological Evaluation of Land-uses and Land Treatments Economic Evaluation and Statistical Techniques Transfer of Technology Watershed Management Concept and Framework Index
â&#x20AC;&#x201D;
1
10 18 30
57 68 80 111 153 175 223 258 275 288 337 370 390 409 437 449
CHAPTER 1
INTRODUCTION HISTORY records that Aryans, the first outsiders, who came to India, were mainly pastoral and agricultural people. Naturally, the major forest areas remained untouched as they settled in the plains, along the river fronts. During the march of Alexander from the north into die Indo-Gangetic plains, it was reported that his entire army was concealed under the cover of dense sal forests of the region on his route. It is perhaps, later on, that the country experienced the trauma of large-scale denudation of forests. These activities must have caused intense erosion leading to siltation of rivers and abandonment of traditional river transportation systems. As a result, many flourishing old port towns like Surat and Cambay are reduced to mere images of their ancient past. The pace of agricultural settlements in cleared forest lands increased for various reasons after India was annexed by the British. In fact, under their â&#x20AC;&#x2DC;Grow More Campaignsâ&#x20AC;&#x2122; during the wars, even hilly areas, as the Nilgiris in the South, were brought under the plough. These exploitative campaigns must have accelerated the erosion hazards in the country. In our country, out of an estimated 175 million hectares of degraded and cultivated lands (Anonymous, 1982), nearly all of them are subject to serious erosion hazards of water and wind, shifting cultivation, waterlogging, salinity and alkalinity and changing water courses (Figs. 1 and 2) (Table 1). There is very little
W,:
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Fig. 1. Erosion by wind
yd
2
SOIL AND WATER CONSERVATION RESEARCH
ÂŁ
S
I
i
1 Fig. 2. Stream bank erosion
area which is free from the hazards of erosion. The arid areas are subject to severe wind erosion. The semi-arid regions, the foothills of the Aravallis and the Siwaliks are subject to severe sheet and gully erosion. The ravines of the Yamuna and the Chambal are continuing to move into the fertile Gangetic plains. People are still
Table 1. Broad distribution of soil erosion and land degradation problems of India under different land uses and special problems (area in lakh ha) Landuse
Problem area
Cultivable land Forest land
1046.7 194.9
Area not available for cultiÂŹ
vation and not under forest Special problems Gullies and ravines
79.1
Alkali
69.9
Saline Shifting cultivation Riverine lands (Khadarldiaral RaolCharlbill) Torrents, stream banks Desert Coastal sandy land Waterlogged areas
Total
39.7
Threatens another 40-60 lakhs ha of productive table lands.
28.5 24.8 2.5 187.9 16.3 59.9
1750.2
or 175 million ha
INTRODUCTION
â&#x20AC;˘
3
trying to cultivate much of these areas, and, thus, contributing to furtherdestruction. Owing to heavy rainfall in the north-east region, floods, stream- bank cutting and sand bar deposition have made farming a very hazardous task. The south and south-east are characterized by rugged and undulating terrain with a high degree of erosion in the black and red laterite soils. The activity of road building and laying of rail tracks have blocked drainage ways in the flatter areas which have resulted in waterlogging. Lack of adequate drainage has led to the loss of cultivated lapds. Road construction and mining activities in hill areas have resulted in serious landslips. Loss of agricultural lands has forced the people to encroach on to steeper scopes and marginal lands for agriculture. Soil erosion has thus been occurring since the time immemorial. In the early years, the problem was more localized. Lack of communication and relatively low population pressures on land served as a check on the restricted exploitative tendencies. But now the problem has become more serious with increasing pressure of population and exploitation of natural resources.
Pressure on Soil and Water Resources Soil and water are the basic resources of the country and must be conserved as carefully as possible. The pressure of increasing population neutralizes all efforts to raise the standard of living and of nutrition, while loss of efficiency in the soil itself nullifies the value of any improvements made. The present position is very serious, all experts agree. It is well known to every farmer that it is the top-soil layer which sustains agricultural production and once this layer is lost or destroyed, nothing can ever replace it. In the words of Lord John Boyd Orr, the first Director-General of FAO in 1948, "Increases in agricultural production are possible through modem methods. But these advances in science will be useless, unless there is enough good land for farming. If the soil on which all agriculture and all human life depends is wasted away then the battle to free mankind from want cannot be won ". To feed the worldâ&#x20AC;&#x2122;s population in the year 2001, agriculture production has to be increased by 60% and this was expected to come from an intensification of agriculture on lands already under cultivation. In addition, FAO expects that an additional 200 million hectares (FAO, 1979) of cultivated lands would be required to meet the additional food demands. An uncertainty in these estimates is the amount of land, being lost through degradation. Total historic loss of land through soil degradation is put at 2 billion hectares, the present arable area of the world being about 1.5 billion hectares. Kovda (1977) has put the annual loss of productive land at 5-7 million hectares. In India, out of 328 million hectares of geographical area, 68 million hectares are critically degraded while 107 million hectares are severely eroded (Anonymous, 1982).
Soil Erosion While the effects of land degradation, especially through erosion and salinization are well known, there are only general estimates of the affected areas. This lack of precise information is felt both at global and national levels. Laflen et al. (1976) estimated that 1 million acre feet of sediment is deposited in the
4
SOIL AND WATER CONSERVATION RESEARCH
American reservoirs, occupying a water storage volume that costs 100 million dollars to develop. Erosion may be defined as the detachment and transportation of the soil. Running water, wind, waves of the sea and moving ice cause a certain amount of erosion called geological or natural erosion. This natural erosion may not always be harmful. However, when natural vegetation was cleared for agricultural purposes, the natural protection that the soil had, was disturbed and the soil detachment and movement occurred at great speeds. Usually, we are too late to realise how our lands are getting eroded until the subsoil is exposed and rills and gullies have formed. The top-soil is our supporting layer and it is upon the productiveness of this layer that our survival and prosperity depends. As a matter of fact, weare only 15 cm away from our annihilation, this 15 cm being our top-soil. Erosion of soil is a part of a vicious circle. The soils are impoverished in this process, dislocated from the one place to the other leading to the deposition of the soil on lands in lower regions, in reservoirs, in waterways and harbours. We hear and see disastrous floods all over the country so often. Nothing better can be expected from exposed watersheds devoid of all vegetation that protects the land. Soil Conservation in the Past Soil conservation is the only known way to protect the productive lands. In a predominantly agricultural country like India, where droughts and floods cause chronic food scarcity, soil conservation can not only increase crop yields, but also prevents further deterioration of land. Methods to control surface run-off and soil erosion have been practised in india from times immemorial. In the ancient India, conservation of soil and water was part of the religion. Even in the recent past, long lines of bunds made of stone or earth are a familiar feature in the rolling terrains below a long range of hills like Eastern and Western Ghats. Further, large tracts of old terraced paddy lands on the hill slopes and in the valley areas are commonly seen in hills of Himalayas, Satpura ranges and Eastern and Western Ghats. Irrigated bench terraces were built by Apatans of Arunachal Pradesh for rice cultivation nearly a century ago. Many minor tanks (tals) were constructed in South India in scarcity areas to retain silt and water from upper catchments and also to store the rain water. Soil and water conservation measures, like contour bunding, were extensively practised in Deccan during scarcity periods to provide relief to the people. Some of the erstwhile princely states also took up programmes of afforestation and gully-erosion control. Though the science and technology of bunding, trenching, gully plugging etc. were understood by many, their application was only confined to Government lands and soil conservation activities were restricted only to limited areas. Legislation was also enacted in some states to enforce closure of areas to grazing and indiscriminate exploitation of forests, etc. but still the effect was not there. The progress of soil and water conservation activities in our country since planned development was started is presented in Table 2 (Anonymous, 1984). Flood control by means of reservoirs was first considered for the Damodar as far back as 1863. In fact, in the Damodar Valley Corporation Act of 1948, the
5
INTRODUCTION
Table 2. Financial progress under State Sector Scheme of soil conservation (Anonymous, 1984) (Rs in lakhs)
Up to
Sixth
1979-80)
Plan
Actuals (1980-83)
AnticiÂŹ pated
outlay (1980-85) Andhra Pradesh Assam Bihar Gujarat Haryana Himachal Pradesh Jammu and Kashmir Karnataka Kerala Madhya Pradesh Maharashtra Manipur Meghalaya Nagaland Orissa Punjab Rajasthan Sikkim
Tamil Nadu Tripura Uttar Pradesh West Bengal Total states: Andaman and Nicobar Islands Arunachal Pradesh Chandigarh Dadra and Nagar Haveli Delhi Goa, Daman and Diu
907 931 1636 3740 588 1130 618 3961 1034 6007 15833
(1983-84)
360 750 2000 2900 1000 1577 550 2080 1029 3800 1588 550 700 600 600 2060 565 622 1800 697 4448 2000 32316 165
135 428 829 1840 430 518 258 1783 562 2639 2896 416 454 362 64 840 216 386 1201 435 3452 568 21011 58 390 5
107 237
850 10 85 91 125
445 64
277
875 545 969 2165 776 314 2897 535 6901 1035 53674 66 302
Proposed (1984-85)
61
190 355 615 230 228 109 465 195 920 1775 135 255 108 150 510 63 142 452 172 1515 211 8856 36
80 258 355 650 284 287 197 460
212 1079 2080 182 265 141 190 507 129 170 494 180 1053 243 9496 46
290
44
175 2 26
9 97
4
18
3 18
680 34
310 19
110 9
200 9
1305
2040
937
380
594
Grand Total
54979
34356
21948
9236
10090
Total expenditure up to
83-84
Lakshadweep Mizoram Pondicherry Total Union Territories
5 79
54979+21949 +9236
=
3
25
86164 Lakhs
responsibility for soil and water conservation in the catchments was also incorporated but only a sum of Rs 7.24 crores were allocated over the period from 1950-56 to cover an area of 400,000 ha.
6
SOIL AND WATER CONSERVATION RESEARCH
Soil Conservation Research in India The widespread soil erosion problem and its impact on total economic life of our country was realised by the Government of India and during the First and Second Five-Year Plans, a chain of Soil Conservation Research, Demonstration and Training Centres was established (Table 3). Table 3. Establishment of S oil Conservation Research Demonstration and Training
Centres Location Dehra Dun Ootacamund Chandigarh
Bellary Kota Vasad
Agra
Ibrahimpatnam
Region
North-western Himalayan region Southern hilly high rainfall region Sub-montane tracts in the northÂŹ western region of India with special reference to Siwalik hills Black soil region (semi-arid) Ravine problem on the banks of the Chambal river Ravine problem on the baiks of Mahi river (Gujarat) Ravine problem on the banks of Yamuna river Red soil region (semi-arid)
Date of establishment
20.9.1954 20.10.1954 1.10.1957 20.10.1954 19.10.1954 11.5.1955
1.10.1957 12.10.1962
The above Centres were transferred to the Indian Council of Agricultural Research (ICAR) on October 1967. The ICAR combined these Research Centres and established on 1 April 1974 the Central Soil and Water Conservation Research and Training Institute (CSWCRTI), with the headquarters located in Dehra Dun. The Soil Conservation Research Demonstration and Training Centre, Hyderabad, became the headquarters of the All India Co-ordinated Research Project for Dryland Agriculture and is now the Central Research Institute for Dryland Agriculture (CRIDA). Six other Centres at Chandigarh, Kota, Vasad, Agra, Ootacamund and Bellary became the Regional Centres of the CSWCRTI, DehraDun. In addition to these research centres, a Desert Afforestation research station was established at Jodhpur in 1952, which was later redesignated in 1957 as Desert Afforestation and Soil Conservation Station. It is now the Central Arid Zone Research Institute (CAZRI). These Centres have been conducting research on regional soil and water management problems for the past 30 years or more. Although soil erosion is as old as the earth, the detailed scientific studies on soil erosion in our country has thus started only 30 years ago. Initially the research work was mainly concerned with constructional aspects of check dams, terraces, etc. and these required only minor modifications from available knowledge whether it was in America or India. The present day soil conservation research and management looks on much of the available knowledge as merely the foundation on which to build and emphasize such aspects as correct land use, improved crop management and protection of the environment.
4
7
INTRODUCTION
A Review of Soil Conservation Research in the World The first scientific studies on soil erosion control were carried out by the German Soil Scientist, Wollny between 1877 and 1895 (Hudson, 1971). Small plots were used to measure a wide range of effects, such as that of vegetation and surface mulches on the interception of rainfall and on the deterioration of soil structure, and the effects of soil type and slope on run-off and erosion. Apart from this pioneer work, the lead in erosion research has come mainly from the United States of America in Forest Service in the form of experiments laid down in Utah and Missouri during 1915-1917. These were followed later on by Benett who established a network of 10 field research stations in the USA during 1928 and 1933 and in the next decade, expanded to 44. These research stations carried out various experiments on mechanical erosion control and run-off from small watersheds. These studies were mainly concerned with field studies and the first critical analysis of the mechanical action of raindrops on the soil was reported by Ellison in 1944. Stallings (1957) aptly described these developments in the following manner: "The discovery that raindrops’ splash (Fig. 3) is a major factor in the water-erosion process marks the end of an era in man’s struggle with soil erosion and ushers in another, which, for the first time, holds out hope for a solution of the problem. The exact nature of the effects of raindrop splash is the phase of water erosion process that escaped detection during the first 7,000 years of civilization. It explains why the efforts at protecting the land against scour erosion in these 7000 years have failed". Ellison’s study has demonstrated that falling raindrop is a complete erosive agent within itself and that little or no erosion occurred when the ground surface
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.
**
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JfP
7
!
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Fig. 3. Splash erosion
8
SOIL AND WATER CONSERVATION RESEARCH
was protected by adequate vegetative cover. On the other hand, Bennett et al. (1951) felt that: "Some recently published statements with respect to the effects of raindrop splash have left the impression that this is the most important factor having to do with the erosion process. It is an important factor, but as already pointed out, it is only one of several factors having to do with erosion of farm lands. As a matter of fact, the cutting and abrasive effect of run-off from rains and the melting snow are of far more importance than raindrop splash, which makes its principal contribution by hurling soil particles into suspension in the run-off. However, the need for research on splash erosion to support field experimentation was realized by most workers, and in the USA, much emphasis was put on this aspect. Analytical research was directed to more specific objectives using field data and modem techniques of analysis (Wischmeier, 1955). Asa result of this study, the main features in theerosion process were identified and mathematically enumerated, which ushered in the present phase of quantitative scientific investigation. Research on erosion problems has not been confined to America. Africa has been well to the fore with the first run-off plots established by Prof. Haylett in 1929 at the University of Pretoria and by Staples in Tanganyika in 1933. Today, a netÂŹ work of field stations is in operation in a dozen or more territories. A notable programme including both field experiments and detailed laboratory studies was carried out in Rhodesia at the Henderson Research Station. International liaison between researchers across this continent has been well maintained, previously by the various technical agencies of the Commission for Technical Co-operation, South of the Sahara (CCTA), the Inter-African Bureau of Soils (BIS) and the Southern African Regional Council for the Conservation and Utilization of the Soil (SARCCUS) and more recently by the Scientific, Technical and Research Commission of the Organization of the African Unity (OAU). Many field experiments have also been undertaken in Ceylon, India, Puerto Rico, Australia, Israel and Japan during the last 10 years but detailed laboratory research on the mechanics of erosion has been limited outside America to a handful of researches. Soil conservation research in India started as early as 1923 with the establishment of Dry Farming Scheme at Manjri near Pune (Kanitkar et al. , 1960). The experiments carried out at Manjri from 1929 onwards to determine the quantity of rain-water lost by run-off and quantity lost by erosion were laid out on the same plan as was followed by Duley and Miller at Missouri in USA. To summarize, the history of erosion research extends back to only 80 years, and the vast majority of the applied or field research has taken place during the last 4Q years. Analytical studies are even more recent; they started with Ellison in 1940 and have been accelerated rapidly in the last 10 years. REFERENCES Anonymous, 1982. SoilConservation Problem, Approach and Progress in India. Soil Conservation Division, Dept, of Agric. & Coopn, Ministry of Agric., Govt, of India., New Delhi.
INTRODUCTION
9
Anonymous, 1984. Report of the Sub-group of the Working Group on Forestry and Soil and Water Conservation for the formulation of Seventh Five-Year Plan (1985-90) for Soil and Water Conservation.Soil Conservation Division, Dep. Agric. & Coopn, Ministry of Agric., Govt, of India, New Delhi.
Bennett, H.H., Bell, E.G. and Robinson, B.D. 1951. Raindrops and Erosion. Circular 895. USDA. FAO, 1979. Agriculture towards 2000. 20th Session of the FAO General Conference, Rome. Hudson, N. 1971. Soil Conservation. BT. Batsford Ltd, London. Kanitkar, N.V., Surar, S.S. and Gokhale, D.N. 1960. Dry Farming in India. ICAR, New Delhi. Kovda, V.A. 1977. Land resources degradation. In Land Resourcesfor Population of the Future. Report on an FAOIUNFPA Expert Consultation, FAO, Rome. Laflen, J.M. and Johnson, H.P. 1976. Soil and water losses from impoundment terrace systems. Third Interagency Sedimentation Conf. Proc. March22 -25, 1976,Denver, Colo, US Govt. Printing Office
2-30,41. Pandey, D.C. 1976. Address delivered at the passing out function of XXXIV RegiiJaj)Course in Soil Conservation in March, 1976. Soil Conserv. Digest. 4(1): 43-48. Stallings, J.H. 1957. Soil Conservation. Prentice Hall, Englewood Cliffs, New Jersey.
Wischmeier, W.H. 1955. Punch card record run-off and soil loss data. Agric. Engng. 36 : 664-66.
CHAPTER 2
SOIL EROSION SOIL erosion is almost universally recognized as a serious threat to manâ&#x20AC;&#x2122;s well-being. The two main agents of erosion are wind and water. In the case of erosion by water, the major erosive agents are impacting raindrops and run-off water flowing over the soil surface. Erosion and sedimentation embody the processes of detachment, transportation and deposition of soil particles (ASCE, 1975). Detachment is the dislodging of soil particles from the soil mass by the erosive agents.
Transportation is the entertainment and movement of detached soil particles (sediment) from their original location. Sediment travels from upland sources through the stream system and may eventually reach the ocean (Holeman, 1968). Not all sediment reaches the ocean, some is deposited at the base of the slopes, the reservoirs, and on flood plains along the way (ASCE, 1975). Erosion occurs in agricultural lands, construction sites, roadways, disturbed lands, surface mines and in areas where natural or geologic disturbances take place. Erosion may be classified as: â&#x20AC;˘ (i) Sheet erosion-the removal of a thin, relatively uniform layer of soil
particles. v /; i
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Fig. 4. Mass erosion in Mussoorie hills
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Publ i sher
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