Dear Murali,
Your post reminds me of my stint with similar soils. Testing, interesting ,character-building exercise, it was! These terrains can break the back and spirit of the most enthusiastic farmers. No reason to be discouraged, still. The vigorous, head –on approach may fail to work here, the soil with its complex behavior will wear down your energy and resources. Prepare yourself for a long-drawn game of say chess, and devise strategies, it will slowly start working.
Your soil is suffering a tremendous handicap. It is highly deficient in one it’s key components, so much that it has stopped exhibiting the true characteristics of soil. Retrace the basics of the soil building process; this will tell you that soil compositions happens when weathered rock (Sand), clay and vegetable/plant matter (humus) bind together. Here the soil is devoid of one component, humus, that has escaped from the composition. Only once this component is restored, the soil becomes fit for cultivation. Plunging big-time into cultivation, without rectifying the soil will result in waste of money, resources, effort and time.
One rarely comes across casualties over 10% wile planting long term crops, under normal circumstances. The normal average of replacement would be 2.5%-5 %. These clayey soils were the exceptions. Saplings are exposed to an extended critical-danger time of nearly 6 months because of the extremes conditions these soils create. About 3 months of water-logging, where saplings yellow, choke and die; another 3 months of soil contraction, compaction and choking, due to which roots get strangulated during summer. Casualty rate planting 1 yr old saplings was as high as 50%. One an average it takes the effort 3 rounds of planting to complete a single round! Interestingly, 2 year old saplings which had established root zones that extended to 12-24 inches under the soil could survive.
The strategy I adopted was 3 pronged.
1)Provide water channels so that excess water drains off. This is to be done with extreme care and caution; or else whatever remains of the top-soil will also be lost. The channels have to be sloped along/across the fields so that the water flows out from the logged areas. Creating depressions/bunds near the growing areas also helps as the water moved out from these areas to the depressions nearby. Make sure that these channels or water ways are filtered at regular intervals; typically a filter can be made of broken bricks, tiles etc that would let the water through and stop the soil.
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Saplings should be grown in sacks/ big containers till they attain a height of 3 feet. Ideally they should be transplanted into the field at that time of the season so the root system gets another 6 months to establish itself deeper,before the next water logging.
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Replenish the soil with plenty of plant matter. This is the only permanent solution to the problem. But where do you source the plant matter from? It has to be generated from the field itself.Having green cover or weeds in the soil would be the first step. From your description it appears that soil is so unfriendly that there’s only one major weed that grows there. No grass? You need to get in more weeds and grass there. Cow dung is a wonderful source of green cover. Ideally the dung from a native Indian breed cow that’s let out to graze. Application of this dung in any form gives you a variety of weeds. An even more effective method would be to find any land that’s been neglected and not weeded. Weeds usually operate in cycles of 3 months; they grow, mature and die, before giving way to the next generation. Select an area of mature weeds, where there are flowering, fruiting or seeding. Let the Cow graze on these or cut these and feed the Cow. When the weeds along with the seeds pass through the Cow’s intestine, they become for sure-shot candidates for germination. A round of Jeevamrutha prepared using this dung should induce some weeds to the soil. It is these weeds, once fully grown, that are to be utilised for plant matter. They will serve the soil well, first by protecting the soil from the Sun and elements, the when they grow excessively, they can be slashed and put back to the soil as plant matter.
Composting is a must for revival of soil humus. If you can propagate cuttings of glyrecidia, dadups, mulberry etc, the supply green leaves for composting. Besides these there are some trees that are suited to water logged areas, like the Kadamb for e.g. As the humus content in the soil increases, there will be change in the behavior of the soil. Water logging and quick drying diminish gradually.
The other methods that you have mentioned, like adding red soil, are expensive as well as unreliable. When red soil is added it will just physically fill out the land. Red soil is mineral. So assign mineral to clay will not bind the soil together. Humus is again required here to bind the elements together.
I do not have any idea about the extent of your holdings, budget etc. I suggest that you try these out in a small sample plot and take things from there only if you are convinced about these methods.
Finally, I pray not to hear there’s a major wind problem in your area. If there is, wind-barriers need to created before proceeding with other operations.
All the best.
cowherd
. I could have copied his methods. Yes I know that life is too short to learn from one’s one experiences !!
. Reason being I have come across some forests during my Treks that has abundance of Clay yet could see good vegetation there .