Stress Management Practices in Rainfed Sorghum (K12) on Yield, Economics and Plant Nutrient Uptake Through Foliar Plant Nutrition Under Typical Vertisols (Typic chromusterts) of Semiarid Region

Abstract

ABSTRACT Foliar fertilization has great potential to give higher yields under intensive cropping system and in enhancing the crop tolerance to drought conditions. Different responses of yield to foliar fertilization are probably associated with incorrect timing of application, use of inappropriate fertilizer and lack of concern of soil available nutrients and environmental conditions. Though soil application of nutrients cannot be replaced totally with foliar fertilization, but under various situations like rainfed condition, foliar nutrition can play very important role in enhancing crop yield and nutrient use efficiency. Focusing on this, a field experiment was conducted in the Agricultural Research Station, Kovilpatti, under rainfed situation from 2017 to ‘20 to evaluate the response of foliar application of plant nutrients sprayed during moisture stress condition and to improve the growth and yield of sorghum under rainfed condition. This experiment was laid out in split plot design with replicated thrice and the treatments consisted of main plots: M1 – foliar spray during dry spell, M2 – foliar spray after relieving of stress/dry spell (with favorable soil moisture) and subplots: S1 – urea@1%, S2 – urea@2%, S3 – water soluble complex fertilizer (19:19:19)@0.5%, S4 – water soluble complex fertilizer (19:19:19)@0.5% + recommended dose of micronutrient for foliar spray (to be decided based on soil test: zinc, boron, iron, manganese, etc.), S5 – ZnSO4@0.5%, S6 – water spray, S7 – control (no spray of any material/water) under rainfed vertisols of semiarid region. The obtained results showed that the application of water soluble complex fertilizer (19:19:19)@0.5% sprayed during the dry spell significantly increased the plant height, earhead length and grain test weight. This attributes resulted in higher grain yield (1448 kg ha−1), stover yield (2288 kg ha−1), net returns (Rs. 8748 ha−1), B:C (1.16) and rainwater use efficiency (3.85 kg ha−1-mm) when compared to other practices in rainfed sorghum. There is a gradual increase in total major plant nutrient uptake, viz. nitrogen (22.3 kg ha−1), phosphorus (4.56 kg ha−1) and potassium uptake (26.0 kg ha−1) with the foliar application of water soluble complex fertilizer (19:19:19)@0.5% applied during the dry spell condition (S3) during drought stress condition (M1). Foliar application of nutrients along with soil application has several advantages in supplementing the nutritional requirements of crops such as rapid and efficient response by the plants, less product needed and independence of soil conditions. Foliar nutrition designed to eliminate the problems like fixation and immobilization of nutrients. Hence, foliar nutrition is recognized as an important method of fertilization during the dry spell under rainfed condition in modern agriculture.