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 CF Crops Using Hand Hoe System |
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ABSTRACT : |
Green revolution areas which are now displaying signs of fatigue, as reflected in the exhaustion of soil fertility and, therefore, need rejuvenation for carrying the green revolution forward. The Budget for 2010-11proposes restoration of soil health through conservation farming involving minimum tillage and ecological balance through biodiversity preservation.
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Conservation farming aims to conserve soil and water by using surface cover (mulch) to minimise runoff and erosion and improve the conditions for plant establishment and growth. It involves planting crops and pastures directly into land which is protected by mulch using minimum or no-tillage techniques.
(*Pl. See Note on Adverse Effects of Climate Change) |
Conservation farming systems are designed to: |
• use mulch cover to reduce soil erosion and land degradation
• reduce soil temperature and conserve moisture for plant growth
• increase organic matter levels and improve soil structure and fertility
• reduce reliance on cultivation
• achieve viable and sustainable productivity.
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WHY WE NEED CONSERVATION FARMING?
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There are many good reasons for the adoption of conservation farming. Some of those are presented below.
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| What will grow when 100 tonnes per hectare of top soil is lost? |
This question will need to be answered if soils in the Top End are continually cultivated or over-grazed. Over 40% of tropical storms result in runoff with the potential to cause erosion. High energy raindrops dislodge soil particles which are carried away in runoff water.
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| Over 100 tonnes of soil per hectare per year can be lost from exposed land in the tropics. |
Mulch cover protects the soil by absorbing raindrop impact, increasing infiltration and slowing the speed at which water runs over the land, thereby reducing soil movement. A study in the Daly Basin showed that conventionally cultivated areas produced twice the runoff and lost on average 1.5 to 6 times more soil than no-tillage areas despite all areas being protected by soil conservation banks. In some seasons notillage areas suffered negligible soil loss while cultivated areas lost up to 8 t/ha. Average soil loss in conventional farming systems in the Top End may range from 20 to 40 t/ha. Continued losses of this magnitude would result in a loss of 1 to 2 cm of top soil over five to ten years.
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Better crops and healthier soil |
Mulch plays a vital role in promoting the uptake and cycling of plant nutrients. Earthworm numbers and beneficial microorganisms increase under mulch, improving soil structure and increasing its capacity to hold water and nutrients. Up to 90% of the nitrogen, phosphorus and potassium lost from farming systems can occur through erosion. Mulch helps to reduce this loss and also acts as a storehouse for many essential nutrients which are gradually released and used by plants.
Conservation farming provides more reliable yields than those achieved under conventional tillage. In a four year study at Katherine, no-tillage grain sorghum averaged 3.22 t/ha while conventionally sown crops averaged 1.80 t/ha.
In dry seasons, conservation tillage has produced double the yield of conventionally sown crops.
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Farming with less energy, labour and machinery |
Machinery and fuel costs have risen by over 500% in the past 20 years. Fuel is now the largest single cost, with tillage consuming over 11% of total energy used on farms. Ploughing and cultivating can use between 6.0 and 17.0 L/ha of fuel while no-tillage uses between 2.0 and 4.0 L/ha depending on the operation. |
| Extra Expenses in the Initial Years |
No single farming system or technique is perfect for all applications and conservation farming is no exception. Conservation farming involves more planning, management and a commitment to sustainability. Trade-offs are necessary and extra costs may be incurred in the initial years. Herbicides and specialised machinery are needed in most conservation farming systems.
Conservation farming will not always result in higher yields especially in seasons where rainfall is ample and well distributed. The effectiveness of some herbicides is reduced by mulch on the surface as high rates of organic matter 'tie up' many chemicals. |
| Fertilisers such as nitrates and herbicides may leach more readily through the soil due to higher infiltration rates under conservation tillage, however, runoff losses will be reduced. These aspects are being addressed through improvements in fertiliser and herbicide formulation, application technology and better management practices. KRSR/060310 |
 Note on Adverse Effects of Climate Change |
Incomes on the small rain-fed farms in Andhra Pradesh could decline by 5 percent under modest climate change and by over 20 percent under harsher conditions, bringing farmers closer to, and in many cases, under the poverty line. Many of the actions and policies that would build future climate resilience produce development benefits here and now. Focusing on these measures would thus yield a double dividend for development and climate sustainability.
Sugarcane yields are expected to decline considerably (by nearly 30 percent) in Maharashtra, as a result of increased moisture stress caused by warmer climate in the future. |
Farm incomes could substantially decline by over 20 percent.
There is need for aggressively pursuing water conservation and controlling groundwater demand at a larger geographical scale and suggests strengthened support for agricultural research and extension to promote sustainable modes of dryland farming. Yields of major crops in India are projected to decline by 4.5 to 9 percent within the next three decades. World Bank Report |
| Climate change to affect wheat output, ICAR Study |
“In the absence of effective adaptation, the country would lose 3.9 million tonne of wheat yield due to climate change by 2020 and 11.7 million tonne by 2050 and 23.5 million tonne by 2080. Per hectare wheat yield in India is needed to be increased to 3.8-4 tonne by 2020 and more than 4 tonne by 2050 to feed the growing population” |
Climate change to affect wheat output An Expert Team constituted by FAO, in its report submitted in September 2009, concluded that for each 1 degree C rise in mean temperature, wheat yield losses in India are likely to be around 6 million tonnes per year, or around $1.5 billion(Rs 7,000 crore) at current prices. There will be similar losses in other crops and our impoverished farmers could lose the equivalent of over $20 billion (Rs 9,200 crore) in income each year. Rural women will suffer more since they look after animals, fodder, feed and water. Prof. MSS |
In the drought prone belt of Maharashtra, climate projections suggest a significant though more variable increase in rainfall (approximately 20 percent to 30 percent at the basin level) accompanied by higher temperatures of about 2.4 degree Celsius - 3.8 degree Celsius, on average. As a result of the heat stress caused by a warmer climate, sugarcane yields are expected to decline considerably (by nearly 30 percent), even though there may be small improvements in the yields of several dryland crops. |
In Orissa, climate projections suggest a substantial shift in the patterns of rainfall towards the flood-prone coastal regions with a dramatic increase in the incidence of flooding. In some districts rice yields will come down by as much as 12 percent. |
| Cattle effect on Climate |
*FAO says that cattle expel more polluting gases that trigger climate change than carbon-dioxide-spewing cars, as methane traps heat 20 times more than CO2. It has been pointed out that a cow produces more noxious gases than an SUV. We have only 75 million-odd motor vehicles but we have the world’s largest population of livestock — around 485 million, including some 283 million cattle, and the rest, goats and sheep — which collectively emit 11.75 million tonnes of methane. |
