Fertilizer Use Among Maize Farmers in Guinea Savannah Zone of Ghana: The Role of Topdressing Fertilizer

Soil fertility management is key to improving crop yields and achieving food and nutritional security in Ghana. The sustainable use of inorganic fertilizers is therefore critical. The sharp rise in international fertilizer prices during the last quarter of 2021 has been a major drawback for fertilizer use at the local level. This has created a supply deficit of urea fertilizer in Ghana. As a stopgap, the Government of Ghana introduced ammonium sulfate into its subsidy program, even though the fertilizer is known for its acidification effects. This study evaluates the yields of farmers based on the fertilizer used for topdressing. A total of 369 farmers were interviewed, and physical yield cuts were done on 187 farms. The following are the major highlights of the study: • Most of the farmers had access to extension services and reported positive returns on their yields. Less than half of the farmers (42%) belonged to a farmer-based organization (FBO). Although credit requests were low among farmers, credit access, especially in cash form, was high. Maize was largely cultivated under personal or family land tenure systems and, on average, 2.3 kilometers (km) away from the farmers’ residence. Typical of northern Ghana, the cultivated lands were mostly flat. Most of the farmers hired tractor services in their land preparation. Nearly three-quarters of the farms were small-scale, with less than 2 hectares (ha) of cultivated land. • Nearly four in every five farmers used preemergence weedicide. Only about 2% of the sampled farmers controlled weeds exclusively through manual weeding. About 57%, 18%, 15%, 6%, and 5% of the farmers used their own saved seeds, seeds bought from input shops, Ministry of Food and Agriculture (MoFA)-approved seeds, seeds from research institutions, and seeds obtained on the open market, respectively. Most farmers (63.4%) planted maize in July and harvested in October or November. The level of germination varied based on the source of seed, and except for those who used seeds bought from research institutions, farmers had to practice refilling to improve the plant density on their farms. From the data, more farmers who bought seeds from research institutions recorded higher yields than those using their own seeds; this claim was supported by the estimated yield. • The major fertilizers used by maize farmers were NPK 15-15-15, NPK 23-10-5+2MgO+3S+0.3Zn, and ammonium sulfate. On average, a farmer applied 254.1 kg/ha of fertilizer to maize. About 34%, 25%, and 10% of the sampled farmers used ammonium sulfate, NPK compound or blend, and urea fertilizers for topdressing, respectively. Farmers applied their basal fertilizers within two to three-and-a-half weeks after planting and topdressing between four to seven-and-a-half weeks after basal fertilizer application. Most of the farmers, especially those using ammonium sulfate, bought their topdressing fertilizers at commercial price. Most farmers (89%) indicated that the use of fertilizer had improved their yields, and 83% indicated the increase in yield compensated for the cost of fertilizers used in maize production. Farmers adopted complementary good agronomic practices (GAPs), and generally, more than half (50%) practiced row planting, planting at recommended spacing, timely weed control, and use of preemergence weedicide; about 48% planted improved seed varieties; and less than 15% practiced minimum tillage, mulching, and use of organic fertilizers. • The yield level from the 187 harvested (yield cut) farms ranged between 0.6 metric tons per hectare (mt/ha) to 5.2 mt/ha, and the average yield was 2.7 mt/ha. The yield level varied based on regional location and the type of fertilizer used for topdressing. 2 ✓ In the North East Region, the average yield was 2.3 mt/ha. It was highest for farmers who used NPK fertilizers (2.5 mt/ha) for topdressing and lowest for farmers who used ammonium sulfate for topdressing (2.1 mt/ha). ✓ In the Northern Region, the average yield was 2.5 mt/ha. It was highest for farmers who used urea (2.8 mt/ha) for topdressing and lowest for those who used NPK compound or blended fertilizer (2.3 mt/ha) for topdressing. ✓ In the Upper West Region, the average yield was 3.1 mt/ha. It was highest for farmers who did not do topdressing (3.3 mt/ha) and lowest for farmers who used ammonium sulfate for topdressing (3.0 mt/ha). ✓ Small-scale farmers had an average yield of 2.7 mt/ha, while medium/large-scale farmers had an average yield of 2.9 mt/ha, although the former used more fertilizer (277.4 kg/ha) than the latter (200.2 kg/ha). • Regarding the source of seed planted, farmers who used seeds from research institutions had the highest average yield of 3.2 mt/ha and farmers who used their own saved seeds or seeds from MoFA had the lowest average yield of 2.6 mt/ha. Regarding GAPs, farmers who did mulching or minimum tillage had significantly higher yields than farmers who did not. • The fertilizer use efficiency (FUE) among the farmers averaged 14.8 kg of grain/kg of fertilizer. There were, however, variations based on the socioeconomic characteristics and GAPs adopted by the farmers. Most importantly, own land cultivation, medium/large-scale cultivation, cultivation of farmlands closer to homes, and mulching improved FUE. • In addition to the promotion of fertilizer use under the subsidy program, farmers must be continuously sensitized or trained on GAPs, particularly mulching, for sustainable maize production
Adzawla, William, Prem S. Bindraban, Williams K. Atakora, Amadou Gouzaye, Oumou Camara, and Richmond Dogbe. 2022. Fertilizer Use Among Maize Farmers in Guinea Savannah Zone of Ghana: The Role of Topdressing Fertilizer. IFDC FERARI Research Report No. 9.