Articles
Irrigation regimes and fertilisation effects on amaranth yield and soil health under different agroecosystems in northern Ghana
Article number
1468_15
Pages
101 – 108
Language
English
Abstract
In northern Ghana, dry-season vegetable cultivation constitutes one of the few viable income-generating activities available to smallholder farmers, who represent the majority of the regional population.
However, during the dry season, water for irrigation is often subject to competition from domestic and livestock water demands, thereby receiving lower prioritisation.
Consequently, the efficient utilization of irrigation water is imperative.
Therefore, we aimed to investigate the effects of varying irrigation volumes and frequencies and fertilisation treatments on the yield of amaranth (Amaranthus cruentus), a traditional leafy vegetable widely cultivated in this region, through field-based experiments.
From the perspective of agricultural sustainability, we also evaluated changes in soil health by analyzing the soil organic carbon (SOC) content before and after three harvests.
The experiment was conducted at three agroecologically and hydrologically distinct sites: Golinga, an irrigated lowland rice field supplied by a dam; Yapei, a rain-fed upland farming area supplemented by river water during the dry season; and Gbimsi, which relies on reservoir-based irrigation during the dry season.
At each site, four irrigation treatments were applied: 8 mm once per day (Ir1), 4 mm twice per day (Ir2), 2 mm twice per day (Ir3), and 2 mm once per day (Ir4). Additionally, three fertilisation treatments were tested: chemical fertiliser only (CF), chemical fertiliser combined with compost (CFC), and urea combined with compost (UC). The results revealed site-specific responses to the irrigation regimes.
The highest average yields (t ha-1) were observed under the CFC treatment combined with Ir2 in Golinga (6.42), Ir3 in Yapei (9.64), and Ir1 in Gbimsi (11.36). Furthermore, Ir1 consistently exhibited the smallest SOC change (ΔSOC) across all three sites.
The relationship between ΔSOC and total yield varied by location: a positive correlation was observed in Golinga, whereas Yapei and Gbimsi exhibited negative correlations, with Gbimsi having a tight correlation.
However, during the dry season, water for irrigation is often subject to competition from domestic and livestock water demands, thereby receiving lower prioritisation.
Consequently, the efficient utilization of irrigation water is imperative.
Therefore, we aimed to investigate the effects of varying irrigation volumes and frequencies and fertilisation treatments on the yield of amaranth (Amaranthus cruentus), a traditional leafy vegetable widely cultivated in this region, through field-based experiments.
From the perspective of agricultural sustainability, we also evaluated changes in soil health by analyzing the soil organic carbon (SOC) content before and after three harvests.
The experiment was conducted at three agroecologically and hydrologically distinct sites: Golinga, an irrigated lowland rice field supplied by a dam; Yapei, a rain-fed upland farming area supplemented by river water during the dry season; and Gbimsi, which relies on reservoir-based irrigation during the dry season.
At each site, four irrigation treatments were applied: 8 mm once per day (Ir1), 4 mm twice per day (Ir2), 2 mm twice per day (Ir3), and 2 mm once per day (Ir4). Additionally, three fertilisation treatments were tested: chemical fertiliser only (CF), chemical fertiliser combined with compost (CFC), and urea combined with compost (UC). The results revealed site-specific responses to the irrigation regimes.
The highest average yields (t ha-1) were observed under the CFC treatment combined with Ir2 in Golinga (6.42), Ir3 in Yapei (9.64), and Ir1 in Gbimsi (11.36). Furthermore, Ir1 consistently exhibited the smallest SOC change (ΔSOC) across all three sites.
The relationship between ΔSOC and total yield varied by location: a positive correlation was observed in Golinga, whereas Yapei and Gbimsi exhibited negative correlations, with Gbimsi having a tight correlation.
Authors
M. Yamada, E. Salifu, I.M. Alhassan
Keywords
irrigation application rate and timing, soil organic carbon, smallholder farmer, indigenous crops, Guinea Savanna climate zone, West Africa
Groups involved
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