In the face of rapid land degradation, farmers adopt many kinds of indigenous conservation measures suitable to their location (Agarwal and Narain The ITKs on different soil & water conservation (S&WC) and runoff management practices discussed here are the ones followed by the farmers without any external support. The farmers ITKs are documented for wider dissemination and adoption under similar situations. These have been documented under the National Agricultural Technology Project (NATP) taken up at CRIDA along with 17 co-operating centers.
Mulching is the spread of any material on soil surface. Mulch material may be agricultural waste, green leaf cover of husk, stones and polythene sheet for controlling water evaporation from soil surface. This is used to reduce soil erosion, increase infiltration, reduce evaporation, and reduce soil temperature and to arrest weed growth. A number of traditional practices are being followed for mulching. Some farmers’ practices on mulching, like application of sand, groundnut shell, sal leaf in turmeric, retention of sunflower stalks, pebbles on soil surface, use of crop residue in the field are discussed here.
Farmers of Benakatti in Bagalkot district of Karnataka retain pebbles on the soil surface as a mulching practice (Kallu Salina Hola). The region is characterized by black soil with an annual rainfall of 680 mm. The pebbles are naturally prevailing in that area and act as natural mulch. This practice is cost effective and technically feasible apart from socially acceptable. The farmers don’t remove the pebbles rather retain them on the soil surface. Evaporation is reduced and soil moisture is conserved in such farm lands. This practice has increased the crop yields up to 60% compared with no pebble mulch in the field. However, it is highly location specific practice.
Ibrahimpur village in Bijapur district of Karnataka, receives 680mm of rainfall annually. Farmers from this area generally have black soils and retain sunflower stalks on the field as a mulch . This practice is adopted by medium and large farmers on individual basis. This is in practice for the last 5 years by 10 % of farmers in this area. In this practice, sunflower stalks are left on the soil surface. After harvest of the sunflower crop, the stalks are retained on the soil surface up to sowing of rabi crops. This acts as a barrier for runoff and reduces soil loss, provides more time for the infiltration of rain water and thereby increases crop yields. The stalks are removed before 15 days of sowing of main crops. This helps in soil and moisture conservation in the field. Fertility can be increased if the stalks are incorporated before sowing of the main crop. This practice is cost effective and technically feasible apart from socially acceptable. But the farmers opined that there was higher weed infestation by following this practice.
Pakanagaon village in Kandhamal district, Orissa, is characterized by sandy loam soils and receives an annual rainfall of 1339 mm. The tribal farmers of this region apply Sal leaves as mulch in turmeric crop. Turmeric is a major cash crop. Turmeric is dry seeded during the month of April and May before onset of monsoon. The entire land is then covered with sal leaf mulch of about 20 – 25cm depth. As soon as it rains, the mulch helps to conserve moisture and enhance the soil temperature, which facilitates germination. Sal mulch prevents weed growth. As the raindrops do not directly strike the soil surface, soil remains friable and thus farmers do not take up the intercultural operation. Cost of intercultural operations is thus minimized to a greater extent. Mulch cover also reduces the runoff and soil loss. This practice of growing turmeric with sal mulch cover has been continuing since time immemorial for the above advantages. However, the major limitation for following this practice is the availability of Sal leaves on a continous basis.
Leaving Crop residue on the field is an age-old practice followed by the farmers of Atkot village in Rajkot district, Gujarat. Here, on an average, 500-600 mm of rainfall is received annually. The major crops grown are pearl millet, sorghum, groundnut and cotton. This ITK is followed by all categories of farmers who grow pearlmillet, sorghum etc. It covers 10-15 % of the area. In this practice after harvesting kharif sorghum and pearlmillet crops, farmers cultivate their field and leave the crop residue on their fields. This type of mulch reduces raindrop impact, runoff velocity and increases infiltration rate. It also improves soil structure and reduces sheet and rill erosion. The major constraints faced are difficulty in performing intercultural operations and the decomposition of crop residue.
Sand Mulching is practiced by all category of farmers in Anantapur district of Andhra Pradesh. This practice has been evolved out of experience of farmers and is followed for more than last 50 years. About 20 – 30 % problematic area in the village is covered by this practice. In black soils, sand mulching can be done for any crop under dryland conditions. It reduces soil crusting and promotes pod development in groundnut crop. It is done before sowing in the field. The thickness is less than 1.0 cm. In Anantapur, application of sand @ 40 t / ha is recommended and it is found to be more advantageous in terms of technical feasibility and conservation efficiency. However, the major constraints to follow this prqactice is the availability of sand in large quantities, high cost of transportation and risk of over exploitation of nala beds for sand, thereby, affecting the river regime.
Conclusions
There is a need to enmesh these practices along with the conventional soil and water conservation measures for promoting sustainable development of agriculture. The Indigenous technological knowledge may be suitably modified / refined for dissemination to new areas to increase the crop production.
Acknowledgements
The author gratefully acknowledges the funding by NATP project for carrying out this work. The support and help rendered by the project scientists and staffs of the lead and associated centers are duly acknowledged.
* Principal Scientist, Central Research Institute for Dryland Agriculture (CRIDA), Santoshnagar, Saidabad, Hyderabad–500 059, A.P. India.
References :
Agarwal A. and Narain S.1999. Dying Wisdom, Centre for Science and Environment, New Delhi, p4-24.
Mishra, P. K. (Compiled) 2002. Indigenous Technical Knowledge on Soil & Water Conservation in Semi-Arid India. NATP, Central Research Institute for Dryland Agriculture, Hyderabad, India, 151p.
Dr. Prasanta Kumar Mishra
