Maize Yield Response to Zinc Fertilization in Farmer’s Field under Rainfed Condition in Hill Region of Assam, Eastern Himalayan Region

Zinc (Zn) is the micronutrient that most commonly limits maize yields but it receives much less attention than other inputs. The present field experiment was conducted to study the effect of Zn fertilizers on growth and yield of maize in farmer’s field under rainfed condition in hill region of Assam, Eastern Himalayan Region for authenticating Zn fertilizer application in increasing the yield of summer maize in actual farmer’s field condition. The experiment was carried out in 6 locations (as replication) of three villages with four treatments which consist of recommended dose of fertilizer (90:40:40 kg NPK kgha-1), recommended dose of fertilizer with ZnSO4 @15 kg ha-1, Farmers’ practice with ZnSO4 @ 15 kg ha-1 and Farmers’ practice (No application of fertilizers) as control. Maize responded positively to Zn fertilization where the yields increased from 4.62 t ha−1 without Zn to 4.91 t ha−1 with Zn under recommended dose of fertilizers. The yield response of maize to application of Zn only recorded 9.15 % increase in yield in case of farmers practice without any fertilizers. Zn application increased maize yield due to increased cob length, cob diameter, kernel numbers and kernel weight in Zn-deficient soils. The increase in grain yield in case of combined use of fertilizer and ZnSO4 (heptahydrate) was mainly due to significantly more number of kernels per cob (392) as well as kernel weight (120.3 g) over application of fertilizers only i.e. 368 and 108.4 g respectively. The result of the present study reveals that, basal soil application of Zn as ZnSO4 @ 15 kg ha-1 in maize crop along with recommended fertilizers is highly recommended for the soils of North Eastern Hill region of India.