The use of sunn hemp as green manure intercropped with taro

Abstract

An experiment was carried out in Magé, Rio de Janeiro State, Brazil, to evaluate the performance of taro (Colocasia esculenta) intercropped with sunn hemp (Crotalaria juncea), used as green manure. A randomized blocks design with four replicates was used and the soil of the field plots was classified as Haplic Gleysol. Treatments consisted of taro (1) intercropped with unpruned sunn hemp, (2) intercropped with sunn hemp cut at soil level, (3) intercropped with sunn hemp pruned at its mid-height, and (4) in monoculture. The taro was planted in double rows spaced by 1.0 m. The planting furrows had a space of 0.5 m, with rhizomes placed at every 3.0 m. The experimental plot consisted of four 3.0 m rows and the useful area corresponded to the five central plants in each of the two central rows. The sunn hemp was sown in parallel lines in the spaces between the taro double rows, 120 days after planting the taro. When the sunn hemp was cut at soil level, an accumulation of 211 kg ha-1 of N was observed. Besides this, the sunn hemp's biomass promoted the cycling of an average 17 kg ha-1 of P, 85 kg ha-1 of K, 151 kg ha-1 of Ca, and 27 kg ha-1 of Mg. Worth mentioning, it represented also a deposition of 6.85 Mg ha-1 of dry substance. Even when pruned at its mid-height, the sunn hemp still provided 60% of nutrients relatively to the treatment in which it was cut at soil level. In addition to the nutrient supply, the use of taro intercropped with sunn hemp cut at soil level or pruned at mid-height represented efficient alternatives for controlling the spontaneous vegetation and for reducing taro leaf burning by solar radiation, without compromising the yield of taro. In all intercropping systems, taro plants had a larger leaf area and were taller than plants in monoculture.

Growth, Physiological Studies and Yield of Taro (Colocasia esculenta Schott) cv. Mukhi Pan as Influenced by Intercropping and Row Pattern under Manipur Condition

“…The result revealed that growth parameters (Table 1) In line with the above findings superior performance of sole crop in terms of plant height, plant canopy, petiole diameter, number of leaves per plant and leaf area was also revealed in the experiments of Oliveira et al, (2007), Chattopadhyay et al, (2008), Osundare and Agboola (2003) and Thirumdasu et al, (2015), respectively. Fresh and dry weigh of plants are important traits, as they are directly related to the dry matter and food reserve accumulation in plants.…”

Green Manure Crops for Management of Meloidogyne javanica and Pythium aphanidermatum

“…Sunn hemp has been used in several tropical cropping systems for control of several nematode species and weeds (Valenzuela and Smith, 2002;Wang et al, 2002Wang et al, , 2008, including a taro intercropping system (Oliveira et al, 2007). An additional benefit from sunn hemp is that it is a legume and can fix atmospheric N 2 , making it a sustainable alternative to synthetic N fertilizer inputs.…”

Intercropping of taro and sunn hemp with cutting periods during the cycle

“…A study by Oliveira et al (2004) focused on the involvement of the taro consortium with sunn hemp and demonstrated its ability to produce significant amounts of N in the plant biomass. The taro and sunn hemp consortium also promotes nutrient cycling and shows a large increase in the organic matter due to the high dry matter content after pruning (Silva et al, 2006;Oliveira et al, 2007). This does not compromise the productivity of the commercial rhizomes produced by taro (Oliveira et al, 2007).…”

“…The taro and sunn hemp consortium also promotes nutrient cycling and shows a large increase in the organic matter due to the high dry matter content after pruning (Silva et al, 2006;Oliveira et al, 2007). This does not compromise the productivity of the commercial rhizomes produced by taro (Oliveira et al, 2007).…”