To understand the current status of agriculture and the irrigation method practiced, SVARAJ, a development organization, conducted a study in Arkavathi river basin in Karnataka State. Many among the 50 farmers interviewed felt that the cultivable land is getting parched every year with artificially induced thirst in the top soil. The study is conducted with the hypothesis that dominant NPK macronutrient chemical soil fertility method is either depleting the naturally occurring micronutrients or is triggering off antagonism among micronutrients. Many of the chlorotic plant diseases such as yellow and brown spot occurrence on the leaves are in fact induced by deficient soils and are abiotic in nature. To confirm this hypothesis, SVARAJ took up a pilot study in the area by experimenting different agriculture plant species for reclaiming land, without the application of any chemical fertilizers, pesticides and insecticides.
Through the survey in the Arkavati river basin, and a workshop conducted in this region, Mr. Nanjappa’s fallow land at Alur of Devenahalli taluk was selected for the study. The criteria for the selection of the land were willingness of the farmer, quantum of land available and water availability on the farm.
Current farm situation
The land was left fallow for about 6 years where no chemical residues were present and this was suitable for our project. Mr. Nanjappa had cultivated only ragi (finger millet) along with companion crops like field beans and cow pea in the small area. The history of the land depicted that it had tried with grapes and potato cultivation, which had failed. During the fallow period, about 6 families grazed their cattle and also scraped the land for fodder continuously.
After several visits and discussions, Mr. Nanjappa showed his willingness to be a part of the programme addressing the problems of remediation and transitioning to natural condition. In 2006 we started working. When we walked across the land, we felt as if we were walking on a rock. The heap of soils looked like the work of mice and bandicoots done for their burrows. Throughout the 4.5 acre of land, bunds and contours were completely invisible and rain water had drained all the surface soil. We thought that the soil and water run off is the immediate issue that needs to be addresed.
The first thing we started was restoration of the water aquifer. In the bore well, the water table was just alive at the depth of 320 feet, where as in the neighboring chemical farming plot, the water level was still lower at a depth of 500 to 850 ft. They used 18 hp submersible pumps to lift the water for irrigation. The water available was not good for drinking and was also contaminated with salts. We also came to know that water table was not so deep in all the areas. In some places it was available at 150 ft also. Thus, along with Mr. Nanjappa, we decided not to deepen the bore well but to take the remedial measures to enrich the existing aquifers. We dug up a percolation tank in the upstream for rainwater harvesting followed by complete contouring of the land across the altitude/slope.
The farm soil was tested for its consistency and the mound of soil didn’t show any sign of organic residues and physical stability. Neighbouring farmer Mr.Rajanna advised us not to venture to any kind of cropping without the application of chemical fertilizer and he was right too, as the soil had no element of clay or organic residue; but, we were stubborn with our hypothesis that chemical fertilizers trigger antagonism among micronutrients and further aggravate the crisis in soil. Mr. Nanjappa started arguing about the splendour of bygone agriculture with fertility practices like application of lake bed soil, farm yard manure and cattle urine. We went around tracing fertile lake bed soil accumulation but found good soil in only few places. While returning back we came across huge deserted anthills which flickered some hope in reclaiming marginal soil with the assumption that anthill soil is PH neutral and hence is neither acidic nor alkaline.
During bunding, we found the soil in the upstream area in good condition and Mr. Nanjappa identified this soil as ‘tanuvu kebbe’ meaning red soil with moisture retention capability. While digging the percolation pond to harvest the upstream rain water, we found this red soil up to six feet depth after which the soil turned hard and gravelly. This made us to come to conclusion that the soil in the middle stream with peculiar altitude was also of the same kind which has been eroded now. After contouring the land we found that the water yield of the aquifer was just 6,000 liters in 6 hours of power supply.
Improving quantity and quality of water in aquifers
Around the aquifer, we dug 300 pits of 2 feet deep, and in the first phase of fertility enhancement, mixed dry leaves of Pongamea, banyan tree, farm yard manure, lake bed clay soil with the top soil and allowed it to get decomposed for 20 days. In the second phase of fertility enhancement, Pongamea , neem cakes, vermi compost were filled into the pits and left for fifteen days for further decomposition. We planted drumstick and papaya in intercropping method and planted chilly in the remaining space. After three rains, the colour and taste of the aquifer water was changing. This small change in the water left some hope of good results ahead but parthenium weeds started sprouting and it was big challenge before us. While the saplings got properly acclimatized in to soil we conducted intercultural operations and turned parthenium and other vegetation back in to the soil and mulched the plant basins with un-flowered parthenium weeds. In 15 days, the soil started emitting earthly smell. After 5 rainfalls, the aquifer water started tasting differently; its salty elements were getting diluted with the rain water percolation.
In the bower unit, where the soil erosion was severe, we decided to dig pits of one foot deep for remediation. Again, these pits were filled with the mixture of the farm yard manure, dry leaves, oil cakes of Pongamea and neem, vermi compost and ant hill soil The amended pits were watered and left for fifteen days for decomposition. Here, we went for vegetables such as bottle gourd, bitter gourd and ridge gourd. The germination rate was about 95%. After heavy rains, the ridge gourds became yellowish due to high moisture, but, bottle gourds and bitter gourds were resilient.
In the second year, we started working on the remaining area of the bower unit. We dug 400 pits of 2 feet deep each and packed with biomass, farm yard manures, lake bed soil, oil cakes of neem, castor and pongamea and vermi compost and left for decomposition. Here again we went for drumsticks and planted custard apples in the border as buffer crops. In 45 days, we observed pink earth worms in the amended areas of soil and the drum stick trees were looking flush green. The top soil was again mixed with lake bed soil and dug the area to remove the weeds. These weeds were dried and mulched in the plant basins. After this, we observed various varieties of herbs growing in the region. But, we knew that there is hidden hunger in the soil. We had no reason to go disheartened with this excess of the weeds, among which many were used in local food culture. We used these weeds for mulching. Keshavamurthy the farmers’ son, started grumbling that we will run short of weeds for mulching. We went ahead with one assumption that more the plant residues in soil, more the physical textural consistency. We allowed the weeds to grow until the seed formation and then we cut them and used for mulching. All the time after each rain, the weeds went on sprouting and provided sufficient biomass for mulching the plant basins. At this stage, we observed the colour change in plant basin soil which was emanating earthly smell after rain. Keshava started making links between the earthly smell and the actinomycetes which he studied in his college.
We started to work on the second step of soil amendment. To reduce the moisture evaporation in the summer, we mulched dried leaves of pongamea and Banyan in the plant basin. We started planting cow pea, horse gram and field beans (legumes), as cover crops and also as nitrogen fixers. These plants were allowed to grow but the excess plants were chopped to mulch the basin again and again. We identified a local land race variety of tomato which was thriving even in this marginal soil. We collected the fruits of this ‘cherry tomato’ and broadcasted them in the plant basins. Tomato creepers started growing in the plant basins and were keeping the mulched plant residues in tact.
Adopting polyculture cropping
We learnt a great deal from the locally prevailing polyculture cropping. In this area, Ragi (finger millet) as a principal crop is cultivated with sequential cropping of field beans, niger, maize, mustard and lentils. One of the senior farmers in the area felt that the traditional polyculture cropping method would have been the prototype for all the crops. With this polyculture cropping method, all the aspects of soil fertility, requirements of livestock fodder and family food were taken care of. In polyculture cropping, multiple varieties with varying root depths were holding the soil in tact and were absorbing nutrients from various levels of soil to enrich the top soil. Different parts of the plant cells get decomposed in the soil at various levels and feed the soil biological system which in turn takes care of the crops. Also, various parts of the plant cells develop various enzymes in the top soil which conserve capillary moisture essential during dry spell. Field beans and lentils as nitrogen fixers and Ragi as a ‘nitrogen craving’ crop completed the soil, atmosphere and plant symbiotic system. In polyculture cropping method, pollen and petals of various flowers and shed leaves mulch the land surface naturally.
Future plans
Now we are at the stage of following companion cropping with various vegetable varieties and nitrogen fixing leguminous crops. We achieved two feet length pod formation even in the marginal soil, where as in the soil with enough organic content we got three feet length pod formation last year.
Considering drum stick tree plant basin as the epicenter, now, we are digging another four pits around the epicenter and amend it to suit various crops. Diverse varieties of crops will be planted. To enhance the biological activity, we are considering application of traditionally prevailing probiotic extractions like Panchagavya.
The research team in SVARAJ will continue to work on reclamation of marginal soils. A range of micro organisms can quench the hidden hunger in the soil. They produce various enzymes that are required to mitigate climate change. Reclamation of marginal soil has both economic and larger ecological benefits. It is holistic in the food cycle of soil biosystems, animal and human nutritional system.
L.C.Nagaraj, Research Officer, Svaraj, No.95/2, 6th Main, 15th Cross, Malleshwaram
Bangalore 560 003, Email: lcnagaraj@svaraj.in; lcnagaraj.lc@gmail.com; www.svaraj.in
References
1) Permaculture manual – Bill mollison
2) Transitioning to organic- Dr.Kasturidas in India together. June2004.
3) Soil and Sustainability- Dan Woodward. www.livingsoil.co.in
