eChapters

Conservation Agriculture (CA) is an agro-ecological approach for sustainable crop production and intensification. CA comprises the resource conserving agricultural production practices that aim to achieve more produce at less cost while enhancing the quality of the natural resource base. CA is all about providing multiple options for farmers, endowed differentially. The basic components of CA include drastic reduction in tillage, adequate retention of crop residues on the soil surface, use of economically feasible diversified crop rotations, avoidance of freewheeling and practice of controlled traffic, if possible. These elements of CA are not site-specific but represent unvarying objectives that are practised to extend CA technologies efficiently across all production conditions. No-till agriculture is considered as a revolutionary step in the direction of preventing land degradation and rehabilitation of the resilient but fragile lands. No-till agriculture together with other associated management practices such as direct seeding into loose crop residues to provide soil cover and to conserve soil moisture, judicious choice of crop rotations and agro-forestry tree species constitutes CA. CA is thus being widely accepted as an important component of the overall strategy for enhancing productivity, improving environmental quality and preserving natural resources for food security and poverty alleviation in such areas.  Recent CA trials conducted in Karnataka, Andhra Pradesh and Tamil Nadu seem to bring out that the rainfed tropical India stands to benefit more from CA than the irrigated areas.

Introduction 

Conservation tillage has been defined based on percent cover of the soil surface with crop residue (CTIC, 2000). Quantifying crop residue cover on the soil surface is important for improving estimates of surface energy balance, net primary productivity, nutrient cycling, and carbon sequestration. Quantifying crop residue cover is also an important factor in controlling soil erosion and evaluating the effectiveness of conservation tillage practices (Barnes et al., 2003). Collecting this information by conventional method of survey and line transact are time-consuming, labor intensive, costly and can involve destructive sampling (Morrison et al., 1993). Moreover, field data are limited because they provide point, rather than area information. Remote sensing technique revealed as promising tool in providing such spatial data over a large area in a time and cost-effective manner.

Introduction

The Indo-Gangetic plain (IGP) is of great importance for the food security of India. It extends over 1,600 km with a width of 320 km, including the arid and semi arid environments in Rajasthan and Punjab and the humid and per humid deltaic plains in west Bengal (Shankaranarayana, 1982). During the green revolution period in the early 1960s, production increased through area expansion and intensification of the rice –wheat system. Driving forces included suitable thermal regimes for rice and wheat cultivation, development of short- duration, nitrogen responsive cultivars, expansion of irrigation and an ever increasing demand for food from the rising population. The rice –wheat system, covering an area of around 10 million hectares (mha), is the major cropping system in the IGP. These two crops together contribute more than 70 % of total cereals production in India from an area of around 25 mha under wheat and about 40 mha under rice. The small states of Punjab and Haryana contribute 20 % of the total national grain production and 50 % and 85 % of the government procurement of rice and wheat, respectively (Singh, 2000).

Conservation agriculture (CA) refers to a set of agricultural practices involving three basic principles of proven scientific soundness. These include continuous minimum mechanical soil disturbance; permanent organic soil cover with crop residues or cover crops; and diversified, efficient, economically viable, appropriate spatial and temporal crop sequences providing opportunities for saving on inputs (labor, fuel, machinery etc.), improving resource use efficiency (water, nutrient, energy etc.) and mitigating GHGs emission with climate change adaptation. Recently research efforts have been made to refine the crop management technologies which are more resource efficient, improve production and income, and reduce GHGs emission compared to the conventional practices. Resource conserving technologies (RCTs) are increasingly being adopted by farmers in the rice-wheat belt of the Indo-Gangetic Plains because of advantages of saving on labor, water, fuel and cost along with timeliness in operations particularly early planting of wheat.

Introduction

The subject of conservation agriculture CA has emerged as a need given the declining productivity of land and increasing costs of input that is putting tremendous pressure on the farming community. Higher yield expectation from land given also brings pressure to the subject of food security. Considering the markets with the globalisation influence is beyond a farmer’s means of influence and price realisation is not a point of control, the situation has deteriorated to their disadvantage. Climate change and soil degradation on the other hand is a reality and agriculture is both a sufferer and contributor, and cannot ignore this reality. Good physical management of soils is one of the key factors to maintain or improve agricultural productivity, in tropical and subtropical regions, and to reduce soil and environmental degradation (Lal, 2000). Tropical soils often have a stable structure and are well aggregated but management practices like intensive ploughing or avoiding the use of cover crops can lead to rapid deterioration (Madari et al., 2005).

Introduction

Rice is grown 43.7 m ha land in India. It is cultivated in 39.51 m ha under kharif and 4.26 m ha under rabi season. As a whole, rice production in India was 104.32 m t (2011-12) with an average productivity of around 2.6 t ha-1. Majority of rice grown in India in the eastern part of the country comprises the states of West Bengal, Orissa, Chattisgarh, Assam, Bihar and Jharkhand. Maximum area under rice in eastern India in West Bengal (5.94 m ha) with a production of 15.04 mt. Productivity was maximum in West Bengal followed by Jharkhand, Assam, Bihar, Orissa and Chattisgarh (DOSE, MOA, GOA, 2011). There is a plenty of scope to increase the productivity of these region with proper policies and technological interventions. Rice area in eastern region (23.4 m ha) would be divided in different ecologies, namely, irrigated (23.2%), rainfed upland (17.9%), rainfed lowland (43.1%) and flood prone areas (25.1%).

Introduction

Development, refinement and adoption of machinery for a range of soil and cropping situations will be fundamental in any success to promote conservation agriculture systems. This chapter reports on the performance of machinery for minimum/zero tillage, bed cultivation system and crop residues management in different cropping system and outlines the need for continuing efforts. Particularly, the focus will be on developing equipments/implements for fixed path / controlled traffic to minimize the ill effects of wheels in the longer terms.

Introduction

In general economic model, technological change in agriculture is expected to cause the commodity supply curve to shift down and out against a stationary demand curve, giving rise to an increase in quantity produced and consumed, and at a relatively lower price. Agricultural economists have used supply and demand models of commodity markets to represent agricultural research impacts, beginning with Schultz (1953) and Griliches (1958), with important subsequent contributions by Duncan and Tisdell (1971), Akino and Hayami (1975), among others. Such a model is explicitly used in many studies. However, low crop productivity, food insecurity, hunger and malnutrition; inadequate farming knowledge and skills, implements and inputs are characteristic of smallholder agriculture in developing countries including India. Many researchers argue that conservation agriculture can guarantee higher crop productivity, food security, improved net income of the farmers and environmental protection, better than the traditional systems of cultivation practices.

Introduction

Soil organisms contribute to the maintenance of soil quality in that they control the decomposition of plant and animal materials, biogeochemical cycling of elements, including nitrogen fixation; the formation of soil structure and the fate of organics and inorganics applied to soils. Soils and their biodiversity thus play a critical role in maintaining soil health. Non-return or diminished return of organic matter and residues deprive the soil biota of their food with loss of soil health and fertility. A large, diverse, and active population of soil organisms is the most important indicator of a healthy soil. The effects of physical and chemical degradation of soils are obvious. But the effects of biological degradation which is caused due to loss of specific soil organic matter (SOM) fractions (and consequently the loss of microbial species/communities dependent on them for nutrition) as well as and specific toxicity influences on soil flora and fauna are insidious. Proper management of soil biodiversity will help in sustainable agriculture and reduce the cost of external inputs especially for nutrient supply and crop protection.

Introduction

Soil biology is the study of the complex system of interrelationships existing among living organisms and their abiotic (physical and chemical) and biotic (living) environments and themselves. The abiotic factors in the environment determine the ability of organisms to live and reproduce. The chemical and physical sampling and analyses provide a broad picture of the parameters that define the aquatic environment. Biological investigation of soil can determine the extent of soil function and activity. To address environmental issues and increase land’s productive potential, we must now go beyond erosion control, soil fertility enhancement and management for soil quality.

Introduction

Carbon is an essential building block of life. It has always been transported from one form or ecosystem to another as a basic part of natural processes. Examples include its transport, through soil erosion, into aquatic ecosystems, or the undersea formation of limestone, the chief component of which is carbon. Much of the world’s carbon is held in soils, including agricultural soils. Another significant carbon pool is in the atmosphere, as carbon dioxide. Ever since agriculture began, between 7,000 and 10,000 years ago, the balance between these two pools has been changing. The loss of soil carbon through soil disturbance has augmented the atmospheric carbon pool. Since about 1750, the burning of fossil fuels has accelerated the process. Carbon dioxide is the largest single agent of climate change.

Climate change is a major issue facing society today with extensive studies being undertaken to find ways to mitigate its effects and impacts in the future. A key factor contributing to climate change is excessive levels of greenhouse gases in the atmosphere and global efforts are focussed on both reducing the emissions of greenhouse gases and increasing the storage (sequestration) of atmospheric carbon.

Introduction

Increasing carbon content in the soil, through better management practices, produce a number of benefits in terms of soil biodiversity, soil fertility and soil water storage capacity and hence productivity. Soil carbon sequestration through the restoration of soil organic matter can further reverse land degradation and restore soil “health” through restoring soil biota and the array of associated ecological processes. In particular, through improved soil water storage and nutrient cycling, land use practices that sequester carbon will also contribute to stabilizing or enhancing food production and optimizing the use of synthetic fertilizer inputs, thereby reducing emissions of nitrous oxides from agricultural land. Conservation tillage practices also reduce significantly the use of fuel and hence gaseous emissions. Soil carbon sequestration is thus very cost effective and could take effect very quickly (FAO, 2008). It also constitutes a valuable win-win approach combining mitigation (CO₂ is removed from the atmosphere) and adaptation, through both increased agro-ecosystem resilience to climate variability and more reliable and better yields (production and income generation). Under climate change scenarios, increased temperature may enhance soil organic matter mineralization in colder regions of the world, releasing carbon dioxide from soils (FAO, 2008). Improved soil management will mitigate the effects of global warming by improved and permanent soil cover. Soil carbon storage was hitherto left out of international negotiations because of envisaged difficulties of validation of amounts and duration/permanency of sequestration. 

Carbon sequestration implies removing atmosphere carbon and storing it in natural reservoirs for extended periods (Lal, 2011). Soil carbon sequestration is the process of transferring carbon dioxide from the atmosphere into the soil through crop residues and other organic solids, and in a form that is not immediately remitted. This transfer or “sequestering” of carbon helps off-set emissions from fossil fuel combustion and other carbon-emitting activities while enhancing soil quality and long-term agronomic productivity. Soil carbon has gained increased interest in the recent past owing to its importance in carbon sequestration studies and its potential impact on sustainable crop production. However, accuracy in estimating soil carbon sequestration to determine best management practices is hindered by inherent variability of soil properties (Srinivasarao et al., 2008 and 2009b). Maintaining or arresting the decline in soil organic matter (SOM) is the most potent weapon in fighting against soil degradation and for ensuring sustainability of agriculture in tropical regions. In India, 65 per cent of agriculture is rainfed, covering the categories of arid, semi-arid and sub-humid climatic zones. Consequences of depletion of organic matter are poor soil physical health, loss of favorable biology and occurrence of multiple nutrient deficiencies. It was stated that in rainfed arid, semi-arid and sub-humid tracts, next to poor rain water management, depletion of nutrients caused by organic matter deficiency is an important cause of soil degradation. Improving organic matter is, therefore, crucial to sustenance of soil quality and future agricultural productivity. Humus is known to favor many useful physical, chemical and biological processes that occur within the soil (Srinivasarao et al., 2011c). Accordingly, 

Introduction

Soil organic matter is an important component of soil quality and productivity; however, its measurement alone does not adequately reflect changes in soil quality and nutrient status. Instead, measurements of biologically active fractions of organic matter, such as microbial biomass carbon and nitrogen, and potential C and N mineralization, could better reflect changes in soil quality and productivity that alter nutrient dynamics. Therefore, measuring microbial biomass is a valuable tool for understanding and predicting long-term effects on changes in land use and associated soil conditions.

Introduction

The basic principle of conservation agriculture is to minimize soil disturbance in order to stabilize the soil structure, increase the fertility and balance the eco-system. Applied together, conservation agriculture practices – no tillage, permanent soil cover, use of crop cover and crop rotation, residue management- have complementary positive outcomes; no tillage maintains soil structure and biological activity; a permanent soil cover protects the soil surface from erosion and creates a stable and favourable micro-climate; cover crops and residue management provides organic matter, reduce soil erosion and improves soil fertility. Management of the soil water balance should be considered as a positive for cover crops and improvement of soil water infiltration, reduction in soil water evaporation, and decreasing water extraction from the soil would impact subsequent plant growth.

Introduction

“Conservation agriculture (CA) is a concept for resource-saving agricultural crop production that strives to achieve acceptable profits together with high and sustained production levels while concurrently conserving the environment” (FAO, 2007). Aspects of conservation that we normally deal are the management of soil, water, crop diversity, animals, storage of produce (seed, fertilizer, etc.), and maintenance of tools, implements, machinery, etc. Some of the important key principles of conservation agriculture are illustrated as (i) Tillage: practice of minimum mechanical soil disturbance which is essential to maintaining minerals within the soil, stopping erosion, and preventing water loss from occurring within the soil. (ii) Crop residues/Mulch: Managing the top soil to create a permanent organic soil cover for growth of organisms within the soil structure. (iii) Crop rotation: The practice of crop rotation with more than two crop species (iv) Economics: Secure farm level economic viability and stability. To achieve this will involve the development of innovation systems focused on the needs of farmers and will include multiple agents who will use their comparative advantages to adapt the principles of CA to the farmers’ various biophysical and socioeconomic conditions. Crop diversification could also be proved as remunerative.  (v) Environment protection:  The CA has a role to conserve the environment in terms of climate resilient agriculture and emission of green house gases (GHG).

6.1. Principles of farm finance

6.1.1. Five Cs’

Introduction

Accuracy and uncertainty analysis is an important step in preparation of surface map through geostatistical techniques or digital soil mapping approach. It is because that we rely on a map based on how much accurate it is and the degree of uncertainty associated with the estimates while the map was prepared. Any stakeholder for a soil map especially policy makers is interested in accuracy and uncertainty of the map before taking suitable land management decisions involving soil map as an input. Again the level of accuracy and uncertainty depends on the properties for which the map has been developed. If the property of interest is sensitive to environment or human consumption, then the accuracy level should be very high while the uncertainty level should be very low e.g. heavy metal concentration in soil, quality parameters of water etc.

Introduction

The optimum soil pH for plant production is one that is slightly acidic, at this pH soil microorganisms are most active and plant nutrients are readily available. At extremes of high (alkaline) and low (acidic) pH this delicate balance is disturbed and plant nutrients that were in adequate supply can become either deficient or toxic to plant growth. Some essential nutrients such as phosphorous, calcium, magnesium and molybdenum become unavailable if the soil pH becomes too acidic. Acidic conditions will result in a lowering of plant production in farming systems. This will result in reduced profitability and an increased reliance on fertilizers to sustain any form of productive agriculture. Correcting soil pH to a more favorable pH range will increase the availability of essential nutrients.

Jharkhand state lies between 21º58’2" to 25º8’32" North latitude and 83º19’05"to 87º55’03" East longitude covering an area of about 7.97 m.ha. and accounts for  2.4 per cent of  the total geographical area (TGA) of the country. It is bound on the east by West Bengal, on the west by Chhattisgarh, on the north by Bihar and on the south by Odisha. Reliable information on the location, extent and quality of soil and land resources is the first requirement in planning for the sustainable management of land resources. The components of land i.e., soils, climate, water, nutrient and biota are organised into an eco-system, which provides a variety of services that are essential for the maintenance of the life support system and the productive capacity of the environment.