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

Alemtsehay Tsegay,Girmay Kahsay,Jens B Aune,Asmeret Kidane,Girmay Tesfay,Berhanu Abrha

doi:10.4314/mejs.v10i2.4

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. Keywords : Tillage; Intercropping; Maize; Soybean; Tigray; Ethiopia. Please find erratum for this article here: https://dx.doi.org/10.4314/mejs.v11i1.10

Highlights

Sustainable intensification of agriculture is required to feed the ever-growing population and promote economic growth in developing countries like Ethiopia
The result of this study demonstrated that reducing tillage intensity by half for maize production would benefit the farmers in Tigray for various reasons: (i) as evidenced by the Marginal Rate of Return (MRR) analysis, it is economically profitable; (ii) it might reduce soil disturbance due to intensive tillage that deteriorate the soil structure; (iii) it might make the soil loose for enhancement of root proliferation; (iv) it incorporates crop residues with soil; and (v) it prevents early emerging weeds
It was for this reason we combined the different tillage frequencies with sole maize, sole soybean and intercropped maize-soybean cropping systems to evaluate their synergy

Summary

Introduction

The crop is important as it produces more oil and protein per unit of land than almost any other crop, supplies most nutrients and is capable of reducing protein malnutrition (Urgessa Tilahun, 2014) It can be intercropped with maize due to its tolerance to shade and drought, and efficient light utilization (Wright et al, 1988). Land is cultivated 2-4 times for maize and more for tef before sowing Unless such kinds of tillage intensity are reduced, soil degradation (soil erosion, poor soil structure, crust formation, poor infiltration, loss of soil organic matter etc.) could be aggravated especially in dryland areas due to cultivation of lands of erosion-prone soils, deforestation and natural calamities (like high rainfall erosivity).

Methods

Results

Discussion

Conclusion