Light, nutrients and moisture are limiting factors altering wheat crop performance in poplar based agroforestry systems. Among these, light along with nutrients are principal limiting resources resulting in systematic yield and quality reduction of understorey crops. To address this issue, a field experiment was conducted to assess the role of P and K nutrition to enhance yield and quality of wheat crop under poplar based agroforestry system. Experiment comprised of two factors (1) sole wheat and wheat intercropped with 2, 3, 5 and 6 year old poplar plantations (2) P2O5:K2O as 0:0, 60:0, 60:30, 60:60, 90:0, 90:30 and 90:60 kg ha1 with a uniform dose of N (120 kg ha−1) applied to wheat. Growth, yield and nutrient uptake of wheat was related negatively while nutrient content and soil fertility status was related positively to advancing age of poplar. Fertilization of wheat with 90:60 kg P2O5:K2O ha−1 resulted in highest increase in yield (49.6%), N, P and K uptake by grains (58.2, 134.7 and 78.1%, respectively), quality (protein content-5.6%) and soil fertility status (organic carbon 18.6%, available N 7.8%, P 50% and K 13.5%) over control. Therefore, fertilization with 90:60 kg P2O5:K2O ha−1 proved to be the most effective treatment to improve wheat growth, yield and quality under canopies of poplar trees.
