Journal of Agriculture and Environmental Sciences

Simulation of Durum Wheat (Triticum turgidum L.) Phenology, Growth and Yield Influenced by Varying Nitrogen Rates and Irrigation Intervals in Central Ethiopia.

2026-02-03T06:46:12+00:00

Calibration and evaluation of crop model is the first step to use appropriate crop model simulation for researchers to forecast how various factors such as weather, soil and agronomic management practices can affect the crop growth and yield performances. The present study aimed to calibrate and evaluate the CERES model for predicting growth and yield of wheat under nitrogen rates and irrigation intervals in central Ethiopia. The treatments of the experiment were included five nitrogen fertilizer rates (0 kg ha^–1, 46 kg ha^–1, 92 kg ha^–1, 138 kg ha^–1, and 184 kg ha^–1), three irrigation intervals (I₁: application of irrigation water every seven days, I₂: every ten days, and I₃: every thirteen days), and one durum wheat cultivar “Utuba”. The experiments were conducted during the 2021/22, 2022/23, and 2023/24 cropping seasons at Debre Zeit Agricultural Research Center (DZARC) in central Ethiopia. The calibration of the CERES model used one year of field data collected during the 2021/22 cropping season. The data used for model evaluation were collected from two years of field experiments conducted during the 2022/23 and 2023/24 cropping seasons. The result of study indicated that the calibrated genetic coefficient of the Utuba cultivar were 10, 20, 380, 11, 79, 0.8, 80 for P1V, P1D, P5, G1, G2, G3 and PHINT, respectively. On the other hand, the model evaluation showed that the strong agreement between the simulated and observed Utuba grain yields, with the percent normalized root-mean-square error (NRMSE %) values ranging from 2.89% to 6.14%, 2.26% to 14%, and 11.6% to 23.01% under seven days(I₁), ten days(I₂), and thirteen days(I₃) irrigation intervals during 2022/23 cropping season and 3.09% to 8.89%, 5.85% to 8.57%, and 7.20% to 22.5% under seven days(I₁), ten days(I₂), and thirteen days(I₃) the respective irrigation water applications during 2023/24 cropping season. Additionally, the error differences (ED) and index of agreement (d-stat) further supported the model's performance. Overall, the evaluation of CERES model demonstrated good accuracy in simulating the growth and yield of the Utuba cultivar in central Ethiopia, highlighting its potential for studying the impacts of various management practices and climate change scenarios.

Genetic Relationships among Sorghum [Sorghum bicolor (L.) Moench] Lines and Correlation between Genetic Distance and Hybrid Performance

2026-02-03T06:45:42+00:00

In certain cases the improved and released sorghum varieties are not being used by Ethiopian farmers because of lack of farmers preferred traits in the hybrids developed so far. This study was conducted to identify the genetic potential of selected sorghum inbred lines involving landraces, introduced and improved lines and its effect on combining ability and hybrid performance to use for hybrid development. Genetic diversity of 37 inbred lines used for the test hybrids was assessed using 7339 SNP markers. The genotypes were grouped into four clusters, with the Ethiopian landraces depicting clear distinction from the introduced and breeding lines. The result implies that efforts might be needed to bring the best genes from the landraces for the hybrid breeding. Genetic distance between inbred lines estimates based on SNP markers ranged from 0.02 to 0.358 with an average of 0.247, indicating the very narrow genetic distance for this study. The regression analysis indicates that grain yield showed an increment as the genetic distance among parental lines increased. Generally, the genetic distance between lines and regression analysis played vital role in determining which lines showed yield increment. Thus, sorghum lines with desirable trait of interests were properly identified for future sorghum breeding program

Herbage dry matter intake of individual dairy cow using a wireless bite counter for grazing based production system in Ethiopia; a case study

2026-02-16T08:50:15+00:00

Measurement of intake of individual grazing animals remains one of the fundamental challenges to improving efficiency of livestock production. Information about the individual herbage dry mater intake (HDMI) of grazing dairy cow is important for an efficient use of pasture herbage and to ensure the release of adequate nutrients for maintenance and production. However, practical and reliable methods are not available to measure intake of pasture by individual dairy cow particularly for grazing based production system for developing countries. Thus, this research was initiated to estimating HDMI using the wireless bite counter system for individual dairy cow in comparison with other methods. A simple, compact bite counter was used to record dairy cow jaw movements to estimate feed intake. The device is composed of a pendulum, a microcontroller, and a transmitter attached to a collar. The utility of the bite counter recordings in estimating intake was experienced for 16 Dairy cows of which nine Local and seven Holstein Friesian crossbred dairy cows. The experiment was conducted for two consecutive years (2018 and 2019) during the main rainy seasons (June to October) of Ethiopia. For comparison, cage system intake estimation was also conducted using sixteen individual paddocks established in the grazing land of Andasa livestock research enter. The grazing herbage in the paddock dominantly comprised of Cynodon plectostachyus, Hyparrhenia rufa, Paspalum notatum, Setaria viridis and Trifolium species. For the calibration of the bite counter, the correlation between the number of bites measured by personal observation and the values reported by the bite counter was linear with an R² value of 0.74. The average HDMI using the bite counter was 4.2 kg DM/day and 7.7 Kg DM/d for local and crossbred individual dairy cow, respectively. The HDMI could be estimated by applying linear regression to the number of bite counts with R² values of 0.68. In conclusion, the wireless bite counter offer new opportunities for rapid estimation of HDMI. Moreover, the bite counter was easy to attach to the cows using the collar and could be used effectively by farmers in the grazing based dairy production system in Ethiopia.