Time Series Modelling of DAP Fertilizer Demand in Kenya

Abstract

Agriculture for many years has remained to be the backbone of the Kenya’s economy and has been a source of livelihood of the population in rural areas. The report “Agricultural Sector Development Strategy (2022) points that agriculture is the mainstay of the Kenyan economy contributing 26% of the GDP and another 25% indirectly. However, agricultural productivity has stagnated in recent years due to various constraints including poor agronomic practices such as fertilizer application. Fertilizers are an important component in increasing agricultural output. One of the major constraints is understanding the demand for fertilizer across different agroecological zones and timely delivering of fertilizer to the farming communities. Hence, Kenya struggles to make this agricultural input adequate because the country does not manufacture it but relies on imported fertilizer. This study investigated the trend and patterns of Diammonium Phosphate (DAP) fertiliz-er demand in Kenya within a span of 13 years to understand seasonal trends and underlying cycles and de-velop a SARIMA (p, d, q) (P, D, Q) s. The secondary monthly data from 2010-2023 that was obtained from the Ministry of Agriculture and Livestock Development headquarters, Nairobi, Kenya. R-software was then be utilized to analyse data for descriptive statistics, fertiliser demand variability and model fitting. The Box-Jenkins method (model identification, model estimation, model validation) was used to determine the best models for the data. The findings of the study pointed out that the demand for DAP fertiliser can be predict-ed by SARIMA (0,0,0) (2,0,0) [12] w/ mean. These findings are crucial as will play a significant role in pro-moting sustainable farming practices, influencing policy decisions, and contributing to discussions in agri-cultural economics.