Water and nitrogen use efficiency in High-Density Guava (Psidium guajava L. cv. VNR Bhihi) under drip fertigation systems

Abstract

A study was conducted during 2018 -2019 to find out the effect of irrigation and fertigation scheduling on growth and yield of guava (Psidium guajava L.). The experiments were laid out in factorial randomized block design with sixteen treatment combinations which included four irrigation levels (120%, 100%, 80% and 60% of ET) along with four fertigation levels 120%, 100%, 80% and 60% of RDF (240,160,160 g of NPK/ plant/ year). The nitrogen, phosphorus and potassium (NPK) fertilizers were applied through fertigation as well as soil application to test various attributes of 2 years old guava cv. VNR Bhihi under high density planting system. Drip irrigation with fertigation enables targeted water and N delivery to the root zone, improving uptake and reducing losses. Water use efficiency (WUE) and nitrogen use efficiency (NUE) are key indicators of sustainability and profitability. This study quantifies WUE and NUE across a factorial matrix of irrigation and N fertigation levels to identify efficient combinations for VNR Bhihi guava. The highest water use efficiency (198.73 kg ha-1 mm-1, 200.24 kg ha-1 mm-1) was observed in I4 (irrigation at 60% of ETc) and the lowest (52.03 kg ha-1 mm-1, 52.57 kg ha-1 mm-1) in I1 (irrigation at 100% of ETc) during both the seasons respectively. The combination of irrigation and fertigation levels had significant effect on NUE during experimental period. On pooled data basis maximum NUE (129.38 kg kg-1) was obtained in I2F4 (irrigation at 100% of ET + 30, 10, 10 g NPK water soluble fertilizers).