The creeping danger for agriculture may not be from the clouds above or the water levels in reservoirs, but from the slow death of the soil the farmer tills.
In vast swathes of land in the State, organic carbon has depleted to a point where the soil cannot sustain life without extensive human involvement. Meanwhile, erosion, a result of the changes in landscape and agrarian practices, is seeing millions of tonnes of soil being washed away from fertile lands.
These disconcerting findings come from the culmination of a four-year research into the soil in drylands under the Sujala scheme, implemented by the State government with 14 agencies and with funding from the World Bank.
Over 2,500 watersheds have been mapped and a Land Resource Inventory (LRI) Atlas created for each one. The 60-page document catalogues the nature of the soil in individual watersheds and forms a background on what needs to be done to reverse the problems. While micro-nutrient deficiency is widespread — something that can be corrected with the use of the right fertilizer — there are other permanent indicators that have raised concern. For instance, take the critical nutrient of organic carbon that is an indicator of “life in the soil,” productivity and ability to trap nutrients. In over 88% of the land area, it is below the ideal level of 0.75%. More than half the land has carbon content below the ‘danger mark’ of 0.5%.
The disparity is stark in some districts: while in the fertile Chikkamagaluru district, 71% of the land area has high organic carbon content, barely 1% of the land in Tumakuru has the ideal amount or higher.
Principal scientist at National Bureau of Soil Survey and Land Use Planning, Rajendra Hegde said, “It is difficult to recover this organic carbon and ensure the soil has the capacity to hold nutrients. Even with intensive conservation farming and green manure, it may take four or five years to turn bad soil into healthy soil.”
Another concern is soil erosion, which erodes the top soil. With lower soil depth, the ability to retain water or nutrients reduces dramatically.
Mr. Hegde said, “Slight erosion will happen, but most of it is man-made. Considering that rainy days are becoming fewer in number while periods of intense rainfall are on the rise, this erosion will increase. In black soil areas (which dominate much of north Karnataka), moderate erosion can turn severe in two years or so.”
The combined effect of these problems is that a majority of the agricultural land is classified as Class III or below, which signifies a marked dip in productivity of land and farmers’ earnings. Combined with socio-economic factors, it isn’t a coincidence then that several studies are showing a dramatic increase in fallow land where agriculture is no longer practiced.
Source:https://www.thehindu.com/
