Assessment of agronomic and economic benefits of fertilizer use in maize production systems under variable farm size, climate and soil fertility conditions in Karnataka of Peninsular India


29 Apr 2016

2015 Annual Interpretive Summary

A study was initiated in the state of Karnataka to understand the socio-economic and bio-physical aspects of farmers on crop productivity and farm profitability. Two emerging (Ballary and Koppal Taluks) and two established (Hadagali and Harpanahalli Taluks) maize-growing regions were identified and then three villages selected from each Taluk. In each village, 15 representative farmers were surveyed to gather information on different socio-economic and bio-physical aspects of district farmers. The extent of the maize area under cultivation, prevalence of yield gaps, presence of variable soil types, maize-growing season, distribution of farmers with variable resources and farm size, water availability (rainfed/irrigated), access and awareness to information and technology, landscape (undulating or flat topography), gender (male and women farmer) were the criteria used for selection of villages and farmers.

Data collected from the 180 farmers on several socio-economic variables was screened through Principal Component Analysis (PCA) . The screening of variables was based on a) the heterogeneity of the variables governing maize yield and b) those variables with a level of scale measurement were selected for the PCA. The analysis identified five major principal components which explained 77% of the variance within the dataset. The first component considered household size, family labor and hired labor and constituted "labor source in the maize farming" as PC1, which explained 22% of data variance. The second component "farm resource" included three variables namely farm income, farm size, and extent of area irrigated, and explained 17% of data variance. The third component considered "management intensity in terms of nutrient use" involving application of N, P, and organic manure by farmers, which together contributed to 16% of data variance. The fourth component considered "non-farm income and application of K fertilizer" by farmers whereas, the fifth component considered "experience in farming" which together explained 10.5% each of the data variance. The factor scores assigned to each farmer under the identified five principal components were further used for delineation of six potential farm types using hierarchical cluster analysis. Weights of clusters were assigned to each of the 180 surveyed farmers, and then 40 farmers representing the six farm types were chosen for further studies. The selected farmers were assigned with individual yield targets based on the extent of availability of resources. Nutrient Expert® (NE) Maize was used to determine the nutrient recommendation for the assigned yield goal, which was compared with the farmer practice and state recommendation. The maize crop is currently standing in the field and the observations are being recorded to evaluate farm typology based fertilizer recommendations for improved maize yields and better farm profits. The study will be continued through 2016.