Reduced Tillage and Intercropping as a Means to Increase Yield and Financial Return in the Drylands of Tigray, northern Ethiopia: A Case Study under Rainfed and Irrigation Conditions

Abstract

Intensive tillage is a major sustainability concern in cereal dominated cropping systems in the drylands of Tigray, Ethiopia. Hence, on-farm trials were conducted to investigate the yield and economic advantage of reduced tillage and intercropping for two seasons. A factorial experiment in a complete randomized block design was carried out at Adigudom located in Hintalo-Wajirat district in South-Eastern Tigray in 2014 (rain-fed) and 2015 (irrigated). The experiment consisted of four tillage frequencies (zero, one, two and four) and three types of cropping systems (sole maize, sole soybean and maize-soybean intercropping) in three/four replications. Maize, variety "Melkassa 2", and soybean, variety "Awassa 91" were used. Grain and biomass yields, and harvest index of both crops were analysed. Yield advantage of intercropping was evaluated using land equivalent ratio (LER) and partial budget analysis was used for the financial evaluation. The grain and biomass yields of both crops were significantly increased (p<0.05) as the tillage frequencies increased from zero to four in both seasons but the frequent tillage with sole cropping was not economically viable as the two times tillage with maize-soybean intercropping gave 126% greater net benefit compared to the four times tillage sole maize, which is practiced by farmers in the study area. The net benefit was strongly influenced by the main effects of tillage and intercropping in both seasons (p<0.001) and by their interaction in 2014 (p<0.05). Significantly higher LER (1.87-2.12) was recorded from maize-soybean intercropping over sole cropping in all the tillages and both seasons. Hence, two alternative options are suggested that farmers could apply in the drylands of Tigray: (i) keeping the sole cropping culture of maize production, and reducing number of tillages from 4 to 2 that would give 374%and 705% Marginal Rate of Return (MRR), respectively, under the rainfed and irrigated conditions compared to zero tillage sole maize; or (ii) intercropping maize with soybean and reducing tillage frequency from 4to 2 that would give 608% and 585% MRR in the respective growing seasons, compared to zero tillage maize-soybean intercropping. Taking these results into account, two times tillage combined with maize-soybean intercropping can be a good option in dryland areas of Tigray to achieve higher total intercrop yield at a low cost and larger LER. Moreover, reduced tillage can minimize soil degradation and benefit farmers with poor access to draft power or female-headed households constrained with labour for ploughing.

Effect of Tillage Practices and Cropping Pattern on Soil Properties and Crop Yield in the Humid Lowlands of Beles Sub-Basin, Ethiopia

“…In addition to this, zero tilled sole maize had a yield advantage over similarly managed crops with conventional tillage systems [68,46]. Generally reduced tillage with maize soya bean intercrop is the best alternative for resource-poor farmers [64].…”

Intercropping Maize with Faba Bean Improves Yield, Income, and Soil Fertility in Semiarid Environment

“…The area devoted to faba bean is also estimated to be 0.5 million ha, making up 30% of the total area coverage given for grain legumes [ 27 ]. The intercropping systems in northern Ethiopia comprise cereals with cereals, cereals with legumes, and trees with annual crops [ 28 ]. However, continuous adoption of improved maize varieties in the last three decades has changed on farms genetic diversity, increasingly leading to the growth of genetically homogeneous maize varieties.…”

Selected conservation management strategies enhance maize yield stability in the sub-humid tropical agro-ecozone of Upper Eastern Kenya

“…After conducting research for four consecutive cropping seasons in the study area, Kiboi et al 14 reported no significant difference in yields between conservation and conventional tillage systems. This could be attributed to the long period required for yield increment under conservation tillage 15 . Thus, there is a need to incorporate soil fertility inputs and assess their effect on crop productivity over a longer term under conservation strategies.…”