EFFECT OF SOWING DATE AND NITROGEN ON THE PRODUCTIVITY, ENERGY RELATIONSHIPS AND ECONOMICS OF SEWAN (LASIURUS SINDICUS) GRASS IN HOT ARID ECOSYSTEM OF RAJASTHAN

The field experiment was conducted at Bikaner (Rajasthan) during kharif season of 2010 to find out the proper time of sowing and optimize the nitrogen requirement of sewan grass (Lasiurus sindicus) in hot arid region. Results indicated that first date of sowing i. e. first week of July (4th) resulted significantly in higher fresh forage yield (172.2 q/ha), dry matter (59.9 q/ha) yields, CP content (8.71%), CP yield (525.3 kg/ha), net returns (Rs.14,278/ha) and B : C ratio (2.47) over other dates of sowing viz., first week of August and first week of September. While in case of nitrogen, although forage productivity and quality were improved up to the highest dose i. e. 60 kg N/ha and recorded fresh forage yield (98.6 q/ha), dry matter yield (35.4 q/ha), CP content (8.95%) and CP yield (320.8 kg/ha) but significantly increased only up to 40 kg N/ha and maximum values of net returns (Rs. 4,737.0/ha) and B : C ratio (1.51) were also recorded with 40 kg N/ha. Interaction effect of date of sowing and nitrogen on forage and CP yield was significant and data showed that values recorded with first date of sowing under 40 and 60 kg N/ha were at par but significantly higher over rest of the treatment combinations. Maximum values of energy ratio and energy productivity were recorded with the sowing in first week of July (12.7 and 702.8 g/MJ) and nitrogen applied @ 20 kg N/ha (7.3 and 402.8 g/MJ). Overall, it was concluded that for getting higher and economic forage yields, sewan grass should be sown in first week of July and fertilized with 40 kg N/ha in hot arid region of Rajasthan.