Conservation agriculture-related practices contribute to maize (Zea mays L.) yield and soil improvement in Central Malawi

Abstract

Conservation agriculture-related practices (CARP) improve soil fertility, maize yield, and profitability. A study was conducted to generate evidence on the benefits of CARP in the long-term (nine years) in Salima District, Central Malawi. The objectives of the study were 1) to compare the maize yields between farmer practice and CARP interventions in the long-term, 2) to compare soil fertility changes between farmer practice and CARP interventions in the long-term, and 3) to verify the intercropping efficiency of maize with groundnut using the land equivalent ratio (LER) and land equivalent coefficient (LEC). A guiding hypothesis was that the application of CARP improves soil condition and maize yield. Farmer practice (FP) and three CARP [Pit planting + mulching (PPM), Intercropping + mulching (INM), and Mulching (MC)] treatments were tested in the study. INM was also tested for intercropping efficiency. Maize yields in CARP (3.98–4.43 Mg ha −1 ) were significantly higher (p < 0.018) than in FP (1.84 Mg ha −1 ). Soil pH, soil organic carbon, soil organic matter, nitrogen, and bulk density were acceptable for the Malawian soil in CARP compared to FP, suggesting that CARP improved soil fertility properties. There was no significant difference in soil potassium concentration across the treatments (p < 0.0642). The land equivalent ratio for maize and groundnut intercropping in INM was 1.77, indicating beneficial intercropping efficiency. The benefit-cost ratios (BCR) for PPM, INM, and MC were 1.55, 1.90, and 2.26, respectively, indicating that CARP interventions were more profitable than FP (BCR = 0.15). It is concluded that CARP interventions contribute to increased crop yield, income, and soil fertility restoration in the agricultural land. The selection of a CARP intervention should depend on the farmer's main intention, either to maximize yield, soil fertility, income, or a combination.

Effect of Intercropping Maize and Beans on the Maize Yields in Isingiro Town Council, Isingiro District, South Western Uganda

“…Related studies conducted in Western Kenya revealed that intercropping maize with crotalaria, groundnut and green gram showed significant economic benefits because all farming systems improved land productivity, household food and income security over the maize mono crop [18]. The study agrees with related studies conducted in Malawi which revealed that intercropping maize with groundnuts improved soil nutrients, maximized the use of environmental resources, resulting in increased maize productivity [19]. Similarly, studies conducted in Ethiopia, pointed out that intercropping of maize with different crops including soybean and desmodium resulted in reduced termite damage to maize and increased maize yield for the improved farmers' livelihoods [20].…”

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

“…The increase in yields later in the trial period was due to increased soil organic matter, hence increased water retention 46 . In their study, Nyirenda and Balaka 47 found that under conservation agriculture-related practices, including intercropping maize with legumes, mulching, and reduced soil disturbance, increased biological activities on litter/residue, resulting in high production and stability in soil organic carbon and organic matter. Consequently, they observed increased maize yield under conservation agriculture compared to conventional practices.…”

Contribution of smallholder farmers to food security and opportunities for resilient farming systems

“…Also, Smale and Mason (2014) found that smallholder farmers adopted practices that are physically easy to use. Other practices such as mulching (Mutsamba et al, 2020;Nyirenda and Balaka, 2021), crop rotation (Gashure and Wana, 2022), and crop diversification (Beshir et al, 2022) are easy to practice and, as such, showed a high level of CSA practiced (Figure 3A). Perhaps one other common feature among these practices is that they have low capital and labor requirements, which is an advantage to smallholder farmers that do not have enough financial resources to adopt expensive practices.…”