Coupling fertigation and buried straw layer improves fertilizer use efficiency, fruit yield, and quality of greenhouse tomato

Inefficient and over use of nitrogen fertilizer and irrigation water are the severe issues with adverse economic and environmental impacts. In present study, the effect of buried straw layer coupled with fertigation was investigated on fruit yield, water use efficiency and quality of greenhouse-grown tomato for two consecutive years. A randomized block design with three factors; 1) straw: (S-N; no straw and S-W; with straw burial), 2) nitrogen: (N-1; 225 kg ha(-1) and N-2; 180 kg ha(-1) and 3) irrigation; (I-1; 90% and I-2; 70% of requirement) was established. The results showed that under lower nitrogen (N-2) and irrigation levels (I-2), the tomato yield was increased by 16.5% and 24.7% under buried straw layer treatment (SWN2I2) when compared to no straw treatment SNN2I2. However, under higher nitrogen (N-1) and irrigation levels (I-1), fruit yield was reduced by 45.8% and 28.6% under buried straw layer treatments (SWN1I1) when compared to no straw treatment SNN1I1 for two years respectively. The total soluble solids (degrees Brix), soluble sugar content, sugar-acid ratio (SAR) and vitamin C (VC) were all increased under SWN2I2 when compared with control treatment SNN1I1 during both seasons. The 3-way ANOVA indicated that the fruit quality was found more sensitive to buried straw layer and irrigation. However, SWN2I2 treatment increased WUE and FUE significantly under limited nitrogen and irrigation conditions. In addition, TOPSIS analysis ranking indicated that SWN2I2 has the best fruit quality when compared to control treatment (SNN1I1). It was concluded that straw burial could alleviate the stress developed by limited irrigation water and fertilizer for improving fruit yield and quality in the greenhouse-grown tomato.