Analysis of Agro-Climatic Variability and Its Effects on Crop Calendars Among Farmers in Plateau State, North Central Nigeria

Agro-climatic variability, manifested through shifting rainfall onset dates, unpredictable dry spells, and temperature extremes, has introduced significant uncertainty into traditional crop calendars across Nigerian farming communities. In Plateau State, where diverse altitude zones support a range of crops with specific agro-climatic requirements, changing climatic conditions have disrupted established planting schedules and reduced production predictability. This study analysed agro-climatic variability and its effects on crop calendars among farmers in Plateau State. A cross-sectional survey of 104 farmers from three agro-ecological altitude zones was conducted using structured questionnaires and climate perception tools. Data captured observed climate changes, historical planting date adjustments, crop performance trends, and adaptation responses. Descriptive statistics and trend analysis of rainfall records from two stations were applied. Results revealed that average first rainfall dates had shifted by approximately 12 days over the preceding decade, leading 66 percent of farmers to adjust their planting calendars. Potato, wheat, and Irish potato farmers in the high plateau zone reported the most significant productivity disruptions due to shortened growing periods. Traditional indigenous climate knowledge was widely used for planting decision guidance in the absence of formal forecast services. The study recommends establishing community climate advisory services in Plateau State and distributing agro-meteorological bulletins through extension channels. Keywords: agro-climatic variability, crop calendars, Plateau State, climate adaptation, planting dates.