Site-Specific Nutrient Management (SSNM) – Another Green Revolution in Northern Karnataka

Karnataka is predominantly an agrarian state of South India with nearly 71 percent of the population depending on agriculture and its allied activities which contribute 49 percent to the state’s economy. It has varied agro-climatic conditions and topographical features with diversified crops and cropping systems. Karnataka state comprises of ten agro-climatic zones based on soil types, rainfall pattern, its distribution and crops grown. Among these zones, Northern dry zone is the biggest that encompasses a major part of Northern Karnataka and it comprises of Bijapur, Bellary and parts of Raichur, Dharwad and Belgaum districts. This is relatively dry zone receiving about 465-790 mm of annual rainfall, consisting of deep, medium and shallow black soils (Vertisols) to the extent of more than 90 percent.

The necessity: Important crops grown in the region are rice, wheat, maize (corn), sorghum, chickpea, cotton, chilli (red pepper), and sunflower wherein only 13 percent of the area is currently irrigated. In this zone, rice is mainly grown in Bellary district under Tungabhadra project area and other crops are almost scattered over all the districts both under rainfed and irrigated ecosystems. The productivity of the important crops like rice, wheat and chickpea is low while comparing state and national averages, showing scope for yield improvements. The productivity levels are low on account of imbalanced usage of major nutrients like NPK and under fertilization without assessing the available macro and micro nutrients status in the soil. This is one of the main reasons attributed to low yields in the zone.

The system followed: On-farm participatory research-cum-demonstrations were initiated in joint collaboration with University of Agricultural Sciences, Dharwad and PPIC during 2003-2005. The main objective was to demonstrate the effect of SSNM on productivity of important crops of northern Karnataka. Nutrients needs are identified based on soil tests and the treatments were imposed considering set yield goals for each crop and available soil nutrients. This formed the SSNM treatment which was compared with other two treatments viz., recommended dose of fertilizers (RDF) and farmers practice (FP). Five farmers were chosen for each crop under this study.

Lessons of SSNM: The results indicated that nutrients application based on soil requirement and yield targets under SSNM resulted in significantly increased grain yield over FP and RDF in all the crops investigated (Figures 1 & 2).


Figure 1. Yield improvements due to SSNM (2003-04)

Treatment details:

RDF - Recommended dose of fertilizers or official nutrient recommendations (by UAS)
FP- Farmers practice.

On an average, the increases in yields due to SSNM treatments were in the range of 9-35 percent over official recommendations (RDF) and 18-50 percent over farmers’ practice (FP), depending on the crop. Rice has recorded highest yield response followed by wheat, corn etc.SSNM also proved to be economical and profitable at the current prices of input costs. The average net income gains with SSNM practices were up to Rs. 5,010 (US$ 113) and Rs. 7,160 (US$ 161) over RDF and farmers’ practices respectively.

Figure 2. Yield improvements due to SSNM (2004-05)

Treatment details:



Photo 1: Field photos showing differences between treatments

Success of such programmes depends on how quickly the information is disseminated to the farming community. As a part of this programme objective, farmers’ field days and training programmes were also organized near the trial locations and regional research stations.


Photo 2: Farmers’ field days


Photo 3: Farmers meetings involving researchers, extension specialists, Govt. officials, local leaders and bankers.

The final message: Presently, the Government’s emphasis is on achieving a new “Green Revolution” particularly from dry land areas for the sake of food security. SSNM could hold promise in achieving profitable and sustainable high yields in the region.

Sources:Annual Reports (2003-04 & 2004-05), Site-Specific Nutrient Management (SSNM) for Maximization of Crop Yields in Northern Karnataka (Investigators: D P Biradar, Associate Director of Research and Y. R. Aladakatti, Sr. Scientist, Agronomy, University of Agricultural Sciences, Dharwad.

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