Nutrient dynamics in pistachios (Pistacia vera L.): The effect of mode of nutrient supply on agronomic performance and alternate-bearing in dry temperate ecosystem

Abstract The present research was accomplished on 8-year-old ‘Kerman’ pistachio nut ( Pistacia vera L.) to study the nutrient dynamics in the dry temperate ecosystem of north-west Himalaya. We investigated the agronomic performance, alternate bearing behavior, soil fertility indicators and leaf nutrients usually to get higher nut yield and quality mainly as the blooming non-contemporaries during the first (2011) and third (2013) as ‘on’ years; second (2012) and fourth (2014) as ‘off’ years. This study has designed with the objective to determine the effect of different levels of NPK fertilizers and foliar Boron (B) fertilization on vegetative growth attributes, fruit set, nut yield and quality of pistachios. At each harvest season, yield per tree, nut attributes and buds abscission (alternate bearing) were recorded. Lightly cropping trees (‘off’ year) yielded 25.3% less, as heavily cropping trees (‘on’ year). N, P and K fertilizers applied as compounds at the rate of 600 (N 1 ), 800 (N 2 ) and 1000 (N 3 ) g tree −1 ; P at 400 (P 1 ) and 600 (P 2 ) g tree −1 and K at 600 (K 1 ), 800 (K 2 ) and 1000 (K 3 ) g tree −1 and B as boric acid (0.5%) were evaluated in 19 treatment combinations. N 1 P 2 K 2 along with foliar B significantly improved vegetative growth measurements, fruit set, reduced buds abscission, reduced nut emptiness improved nut quality (fruit dimensions and sphericity) during ‘on’ and ‘off’ years of pistachios. Available macronutrient contents of soil (viz., N, P, K) increased by 23.6, 54.3, 29.4%, respectively. Diethylenetriaminepentaacetic acid–extractable (DTPA) micronutrients (Fe, Cu, Zn, and Mn) increased by 36.2, 78.9, 41.9 and 24.2%, respectively. Furthermore, lightly cropping trees (‘off’ year) have more leaf N, P, K and B concentration, as heavily cropping trees (‘on’ year). Correlation analysis of different attributes representing the physical-chemical attributes of soil parameters, nut yield and nut filling characteristics also resulted in a significant association at alpha = 0.05 attribute pairs. Principal component analysis (PCA) of yield, nut filling characteristics and soil physico-chemical attributes was also worked out to evaluate the differences induced among treatment combinations applied. The results inferred that Principal Component-4 (PC-4) accounted for 77.1% of the total variance. Additionally, a great influence of NPK and foliar B fertilization is also showed for all the agronomic parameters studied in this work.