Effect of paddy straw mulch, irrigation regimes and nitrogen levels on the performance of spring transplanted bell pepper in semi-arid environment of South-Western Punjab

Abstract

A 4-years study was conducted to investigate the effect of three irrigation levels (I1= IW/CPE=0.6, I2=0.9, I3=1.2) and three nitrogen levels (N1=100 kg/ha, N2=125 kg/ha, N3=150 kg/ha) on growth, yield, quality and water use efficiency (WUE) of spring transplanted bell pepper with paddy straw mulching (PSM) @ 6 t/ha (M1) vis-à-vis without mulching (M0). Significantly higher fruit yield was recorded with higher number of irrigations (I3) as compared to I1 and I2 levels. The fruit yield under M0I3 was statistically at par with that under M1I2 implying saving of 5-7 irrigations by using PSM. Low nitrogen fertilization with PSM (N1M1) yielded at par with higher nitrogen fertilization without mulching (N3M0) revealing that 50 kg N/ha may be saved by using PSM. The dry matter, ascorbic acid and chlorophyll (a, b and total chlorophyll) in fruits harvested from M1 plots were higher than those from M0 plots whereas, the capsaicin content in fruit was 14.6% lower in M1 plots than those from bare soil. The dry matter, vitamin C and chlorophyll (a, b and total) in fruits were the lowest in I1 and the highest values were recorded in I3 whereas the capsaicin content exhibited the contrary trend. A significant increase in fruit dry matter, ascorbic acid and chlorophyll (a, b and total); and a decrease in capsaicin content was observed with increase in nitrogen dose from 100 kg/ha to 150 kg/ha. Water use (WU) was slightly higher under M0 as compared to M1 plots, whereas, the WUE and profile water use (PWU) were higher in M1 than in M0 plots. The WU and PWU exhibited an increasing trend with increasing frequency of irrigation whereas the WUE showed a decreasing trend. The WU and WUE values were the highest at N3 and the lowest at N1 level. The organic carbon, available nitrogen, phosphorus and potassium content of surface soil (0-15 cm) increased with PSM than those in bare soil.