Development and Evaluation of Customized Fertilizer Formulations for Tuber Crops Grown as Intercrops in Coconut Gardens

Abstract

Tropical tuber crops like cassava, sweet potato, yams and aroids are some of the most important food crops of man since time immemorial. Soil fertility and plant nutrition studies over half-a-century at ICAR-Central Tuber Crops Research Institute (CTCRI) have shown these crops to be highly responsive to the application of fertilizers and manures. With paradigm shift in focus to issues of soil, plant, animal and human health, site-specific/custom-made fertilizer formulations based on soil nutrient status and plant nutrient requirement are gaining importance. An attempt was made to formulate customized fertilizer (CF) formulations for elephant foot yam (EFY) grown as intercrop in coconut gardens of the two agro-ecological units (AEU) of Kerala viz., AEU 3 and AEU 9. Elephant foot yam is a popular tuberous vegetable grown in Kerala, mostly as intercrop in coconut gardens owing to its long shelf-life; nuetraceutical, medicinal and economic benefits; tolerance to marginal environments; high yield potential; and a possibility to grow throughout the season. This paper gives the protocol followed for developing the formulations. These formulations were tested at different locations across AEUs 3 and 9 for two seasons to arrive at the best formulation along with optimum rate of application. Product CF2 with 7:12:24:2.5:1.25:0.4 grade of N:P2O5:K2O:Mg:Zn:B at 625 kg ha-1 was found to be the best. These at the 625 and 500 kg ha-1 rates were again tested for different genotypes of cassava and sweet potato (var. Sree Arun) on station and for greater yam at ICAR-CPCRI under intercropping in coconut.