Productivity potential of cultivated cereals, pulses, oilseeds, grasses, lemon and conservation of natural resources in grassed waterways in north-western Himalayas

摘要

Grassed waterways are developed to serve as safe disposable structures for concentrated runoff, thereby protecting the land against rills and gullies. The studies in beds and side slopes of natural waterway existing at the Research Farm, Selalcui, Dehradun were taken up in two phases; in the first phase (2004-2008), three cropping sequences viz., rice bean-gobhi sarson (Brassica napus) in first segment (1.0% slope), finger millet-lentil in second segment (1.3% slope) and Guinnea grass in the third segment (1.6% slope) with lemon plantations on side slopes were followed during 2004-2008. In the second phase (2008-2016), cropping sequences of first and second segments were replaced with lemon grass without any changes in intercrops of third segment. The study was conducted with two objectives (1) to assess the productivity levels of traditional cereals, pulses, oilseeds and fodder grasses and horticultural plants (Lemon cv. Eureka round), (2) to detain the runoff for longer duration to increase the infiltration opportunity time and retard flow velocities for trapping more sediment in waterway to enhance storage life of farm pond. Subsequent to the reshaping of the waterway in 2004, the productivity levels of finger millet increased from 4.2 q ha~(-1) to 7.6 qha~(-1), and of rice bean from 28.2 qha~(-1) to 49.0 qha~(-1) during kharifseason. Similarly, during rabi season, lentil productivity ranged from 2.0 q ha1 to 3.7 q ha~(-1) and B. napus yield ranged from 3.0 q ha~(-1) to 5.4 q ha~(-1). Water use for evapo-transpiration demand of Panicum maximum was the lowest (145.5 mm) followed by lentil (153.0 mm) and B. napus (160.5 mm). Green biomass production of 18.731 ha1 was recorded in Guinnea grass (third segment). The first segment produced highestaverage fruit yield of lemon which was 11.26% and 27.78% higher than second and third segments of waterway. There was net deposition of sediment to the tune of 15.41 m~3 and 25.4 m~3 in second and third segments, respectively. Designing and reshaping thewaterway, resulted in only 4 overflows from the farm pond in comparison to 10 overflows in previous years.