Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 21 Issue 6

Analysis of Rainfall and Temperature Patterns on Yam Yield in Lafia, Nasarawa State, Nigeria Moses F. Victoria α , J. I. Magaji σ & Iliyasu M. Anzaku ρ Abstract- Analysis of rainfall and temperature patterns on yam yield in Lafia, Nasarawa State, Nigeria. Variability is one of the serious environmental challenges that has received a lot of complaints. This study therefore sought to examine the effects of climate variants on yam yield, data were collected for a period of 15years from the Nigerian Meteorological Agency (NIMET) and the Nasarawa Agricultural development Project (NADP) in Lafia, capital of Nasarawa State. The data were analyzed using the Pearson correlations and linear regression analysis and the trends in temperature, rainfall on yam yields. The result of the study shows an increase in maximum and minimum temperature at 0.168 0 C and 0.413 0 C respectively, coupled with unreliable rainfall of 0.079 over the investigated period (2001-2015), while the standardized coefficient Beta was 0.075. The study indentified poor yield as the major effect of rainfall and temperature variations on yam yield. Maximum temperature had a weak (0.168) positively significant relationship on yam yield for the investigated period, minimum temperature had a weak (0.413) positive significant relationship on yam yield which is more advisable and rainfall had the weakest (0.079) positive significant relationship and it cannot be held responsible for higher crop yield, except if joined with other factors like soil fertility, soil moisture, soil pH, and so on for the 15 years period. It was recommended that crops like yam should be planted in the month of February due to enough heat absorption so it could rapidly grow when the first or early months of rains start, and that Agricultural Extension Officers should be deployed to guide famers through routine visits, sensitization programmes on variability in rainfall and temperature characteristics, use of farm inputs and monitoring of crop-climate relationships in the area in order to achieve improved crop yield . Keywords: rainfall, temperature, pattern, yam, yield. I. I ntroduction ainfall continues to be the most important climatic parameter with the highest spatial and temporal variability over most part of the world. The distribution of precipitation over the earth is considerably more complex than of insolation or air temperature (Oguntoyinbo, et al., 2015). Rainfall is an element of weather. Other elements of weather include temperature, humidity, wind, cloud and sunshine. It is the collective pattern of expression of these elements overtime that becomes described as the climate of a place. Climate is the synthesis of the weather in a given place over a period of at least 30 years. Thus climate is the “average weather” together with the variability from the average. Apart from precipitation, temperature is probably the most talked about weather element. Temperature can be defined in terms of movement of molecules such that the more rapid the movement the higher the temperature. More usually, it is defined in relative terms on the basis of the degree of heat a body has. Temperature is the condition that determines the flow of heat from one substance to another. Heat moves from a body having higher temperature to a body lower temperature. The temperature of a body is therefore its’ degree of hotness as measured by the thermometer. Various scales are used to express temperatures, these include the Fahrenheit, centigrade and Kelvin or absolute temperature scale is used. In most countries temperatures are now measured in centigrade or Celsius scale and in some applications the Kelvin or absolute temperature scale are used. Temperatures on Fahrenheit (F) scale can be converted to Celsius (C) using the simple equation of the form. C =5/9(F-32) (Ayoade, 2004, p.29). Climate refers to the characteristics condition of the atmosphere deduced from repeated observation over a long period. It includes considerations of departures from average (i.e. variability’s), extreme conditions and the probabilities of occurrences of a given weather condition (Ayoade, 2013). Rainfall is an important aspect in both climatic and geomorphologic studies. Amount of rainfall in a given region is influenced by many factors; among them are relief, wind and direction (relative to coastal orientation) and distance from the ocean. For instance, where humid air masses moving across a region are forced to rise over highlands/plateau, it tend to bring about instability resulting in heavy rainfall (Ayoade, 2013). The geographical local of Nigeria, its topographical variations and latitudinal extent dictate the behaviour of the climatic types and its characteristics in the region. Rainfall in Nigeria is the most variable climatic element both in its spatial and temporal distribution as areal-precipitations which is the average depth of precipitation over a specific area calculated on timescales on a storm, seasonal, or annual basis vary from place to place in the country. R 1 Global Journal of Science Frontier Research Volume XXI Issue VI Year 2021 35 ( H ) © 2021 Global Journals Version I Author α σ : Department of Geography, Faculty of Environmental Sciences, Nasarawa State University, Keffi. e-mail: mamman.iliyasu@yahoo.com Author ρ : Department of Science, School of Continuing Education, Bayero University, Kano, Nigeria.