Climate change is a major environmental stressor that would adversely affect tropical agriculture, which is largely rain-fed. Associated with climate change is an increasing trend in temperature and decline in rainfall, leading to prolonged and repeated droughts. The purpose of this study was to determine the effect of climate variables such as temperature, relative humidity, vapor pressure deficit (VPD), and soil water on the phenology, biomass, and grain yield of soybean crops. A greenhouse experiment was set in a split plot design with three average environmental conditions as the main plots: E1 (36 °C, RH = 55%), E2 (34 °C, RH = 57%) and E3 (33 °C, RH = 44%). Additionally, there were three water treatments: W1 (near saturation), W2 (Field capacity), and W3 (soil water deficit) and two soybean varieties (Afayak and Jenguma). These treatments were replicated nine times. The results showed that high temperatures (E1) accelerated the crop development, particularly at flowering. Additionally, increased atmospheric demand for water under a high temperature environment resulted in high evapotranspiration, leading to high transpiration which probably reduced photosynthetic activity of the plants and thereby contributing to biomass and grain yield loss. Biomass and yield were drastically reduced for the combined effect of high temperature (E1) and drought (W3) as compared to combined effect of ambient temperature (E3) and well-watered condition (W1). Increasing temperatures and erratic rainfall distributions associated with climate change poses a potential threat to the soybean production in Ghana.

Assessing soil compaction using soil bulk density as an index for measurement could provide background information on the critical range of soil compaction for groundnut production in Nigeria. Therefore, field experiments were conducted in 2012 (year 1) and 2014 (year 2) to assess the effects of five levels of soil compaction (1.1 Mg m−3 [control], 1.2, 1.3, 1.4, and 1.5 Mg m−3) on groundnut yield. The experiment was laid in completely randomized design with four replicates. Number of Pods (NP) and Fresh Pod Mass (FPM) of groundnut were estimated using standard procedures and subjected to ANOVA at α 0.05. The NP of groundnut differed significantly among the treatments and was reduced by 70.1 and 76.0% in 1.4 and 1.5 Mg m−3 relative to 1.1 Mg m−3 in year 1, while corresponding low values were 40.4% (1.4 Mg m−3) and 48.4% (1.5 Mg m−3) in year 2. It was noteworthy that the NP in 1.2 and 1.3 Mg m−3 were statistically similar. Consequently, FPM of groundnut was in the order of 1.1 > 1.3 > 1.2 > 1.4 > 1.5 Mg m−3 in years 1 and 2, respectively. Hence, soil compaction at 1.1–1.3 Mg m−3 could be critical for groundnut cultivation.