Fertilizer Microdosing in the Humid Forest Zone of Ghana: An Efficient Strategy for Increasing Maize Yield and Income in Smallholder Farming

Abstract

Core Ideas N–P–K fertilizer microdosing increased maize yields by 99% in the humid forest zone. Gleyic Plinthic Acrisol produced higher maize grain yield than the Plinthic Acrisol. Microdosing increased N, P, and K use efficiency of maize in rotation vs. sole cropping. Maize grain yield and net returns were optimal with N20P40K20 and N0P40K20 microdoses. High fertilizer costs pose a challenge in smallholder farming; optimizing fertilizer recommendations that are affordable to resource‐poor farmers could increase crop yield and income. The study aimed to determining the yield and economic effects of N–P–K fertilizer microdosing on maize (Zea mays L.) crops on Gleyic Plinthic Acrisol (GPA) and Plinthic Acrisol (PA) in the semideciduous rainforest zone of Ghana using a split‐plot randomized complete block design with three replications. The field trial included two cropping systems (continuous maize cropping [CMC] and cowpea [Vigna unguiculata (L.) Walp.]–maize rotation [CMR]) as main plots with four treatments (N0P0K0, N0P20K20, N0P40K20, and N20P40K20) and the recommended fertilizer rate (N90P60K60) as subplots. Fertilizer treatment effects on maize stover and grain yields were assessed. The microdose treatments increased maize yields by 32 to 99% across cropping systems and soil types. Maize grain yield increase was higher on the GPA than on the PA. The N90P60K60 and N20P40K20 treatments resulted in higher grain and stover yields than the other treatments across cropping systems and soil types. Among the treatments maximum grain yield increases of 76 and 99% were obtained with N20P40K20 on the PA and the GPA, respectively, under CMC. Under CMR, grain yield increased by 46% with N0P40K20 (PA) and 74% with N0P20K20 (GPA). The largest net return was obtained with N20P40K20 under CMC across both soil types and with N0P20K20 (GPA) and N0P40K20 (PA) under CMR. These fertilizer microdoses can be considered appropriate for increasing maize yield and the income of smallholder farmers.

The determinants of fertilizer microdosing adoption and impact on sorghum and maize yields in Burkina Faso

“…In other words, fertilizer microdosing application on sorghum can on average increase the yield approximately by 55% given others factors. This is consistent with the findings of studies which highlighted that fertilizer microdosing increased significantly crop yield (Pender et al, 2008;Sime and Aune, 2014;Okebalama et al, 2016). Tabo et al (2007) using data from farm test field, found that sorghum yield under fertilizer microdosing was 106% greater than the control in Burkina Faso.…”

“…Tabo et al (2007) using data from farm test field, found that sorghum yield under fertilizer microdosing was 106% greater than the control in Burkina Faso. In Ghana, Okebalama et al (2016) obtained that fertilizer microdosing treatment increase maize yield by 32 to 99 % across cropping system and soil types.…”

P-dipping of rice seedlings increases applied P use efficiency in high P-fixing soils

“…Localized P application—the application of P fertilizer in the root zone, where P is readily accessible to the plants, instead of conventional broadcasting or incorporation—is one of the most studied options for improving applied P use efficiency 10 , 11 . A number of studies have demonstrated significant increases in grain yield and applied P use efficiency with localized P application for upland crops such as maize, pearl millet, sorghum, cowpea, and groundnut 12 – 16 . Positive effects of localized P application have been observed in direct-seeded upland and lowland rice production systems where small amounts of P are placed along with planting 17 – 19 .…”

Analysis of labor opportunity cost on the economic profitability of fertilizer microdosing (FM) in Burkina Faso

“…In terms of impacts, the results of previous studies showed a significant income increase for farmers who adopted fertilizer microdosing as well as an improvement of their food security (Okebalama et al, 2016;Fatondji et al, 2016;Bagayoko et al, 2011). However, the analysis of these studies revealed that not all the additional costs such as labor cost were taken into account particularly in the economic profitability evaluation of fertilizer microdosing.…”

“…Indeed, the application of fertilizer microdosing generates an additional cost in terms of labor due to the greater effort needed to bury the fertilizer compared to the traditional practices (Liverpool-Tasie et al, 2015;Pender et al, 2008;Tovihoudji et al, 2018). In addition, analysis of the results of empirical studies indicated that labor availability would be one of the main constraints affecting fertilizer microdosing adoption (Okebalama et al, 2016;Tabo et al, 2007). This labor constraint led researchers to work on how to mechanize the application of fertilizer microdosing for a wider adoption by farmers (Tabo et al, 2007).…”