Effect of Different Irrigation Patterns on Oat-Vetch Mixed Forage Production System in Rasuwa, Mid Hills of Nepal

Abstract

The scarcity of forage resources, particularly in Nepal's midhills, poses a challenge to the sustainable development of livestock production. In order to address issues, an experiment was carried out in 2020 at Kalika Municipality in Rasuwa District, Nepal, to determine the best forage combinations in terms of total dry matter productivity. With irrigation as a main plot effect, a 4*3 factorial RCB design was used with four replications. Crop species included oat (Avena sativa, Kamdhenu), common vetch (Vicia sativa), and combinations of oat and vetch within a sub plot. Irrigation treatments included none, once per month (30-day interval), twice per month (15-day interval), and three times per month (10-day interval). Temperature and precipitation data from nearby stations were taken from the Department of Hydrology and Meteorology. The first harvest was taken after 65 days of sowing (DAS), with consecutive harvests after 35 days of the initial harvest. The experimental findings revealed that the first, second, and total dry matter production were altogether found highest in the three times irrigated plot (2.47±0.25, 1.38±0.21, 3.85±0.46 respectively) and lowest in the rainfed condition (1.37±0.22, 0.69±0.12, 2.07±0.33 ton/ha respectively) with statistically highly significant result (p<0.001). The oat and vetch mixed cropping pattern had statistically higher dry matter production in the first (2.66 0.14 ton/ha), second (1.5 0.13 ton/ha), and overall average total production of (4.16 0.25 ton/ha), among the subplot effect (species). Additionally, among the subplot effects, the oat and vetch mixed cropping had the highest dry matter production in terms of first harvest yield, regrowth, and overall yield (p<0.01). Oat sole cropping could be replaced with mixed cropping of oat and vetch at a ratio of 50:50 (50:10 kg ha-1) because it produced the highest yield advantage, including forage quality. These findings provide scientific support for common vetch-oat intercropping as a sustainable approach to increase forage production with 10-day irrigation interval. These mixtures appear promising for the development of sustainable crop production with low external input and higher economic yield, and they can be used as a viable option by farmers in rainfed mid-hills of Nepal