Land-use land-cover change due to government policies and strategies to support the livelihood of the community became common practices in the agricultural landscape of Debrekidan in Tigray region, Ethiopia. Regardless of the land-use change happened in this landscape, study on physicochemical and microbial soil properties across the land uses is notably scant and little is known on how farmers could manage their land. The objective of this study was, therefore, to investigate the impact of land-use change on physical, chemical and microbial soil properties. A total of 86 composite soil samples from a depth of 20 cm were collected from four land uses: area closure, grazing land, rain fed and irrigated agricultural lands. Soil parameters mainly investigated were soil texture, pH, EC, organic carbon (OC), total nitrogen (TN), available P, K, and rhizobia population. The analysis of variance indicated that land use had a significant effect on OC, TN and pH at (p < 0.05). Higher OC and TN were found in grassland, whereas, higher pH was found in irrigated land. Higher rhizobia population densities were found in grassland whereas lower rhizobia population were in rain fed cultivated land. Generally, the agricultural landscape is characterized by low OC, TN and rhizobia population; and optimum phosphorous and potassium. Therefore, farmers of the watershed and other similar areas have to use soil management options that enhance soil OC, nitrogen and rhizobia populations.

Water quality degradation is one of today's key environmental challenges. Once contaminated, its treatment becomes difficult and prohibitively costly. Therefore, efficient and sustainable groundwater management is essential to conserve this vital resource. This is particularly true for the Elalla-Aynalem catchment, which serves as the primary water source for Mekelle town. This study aimed to produce optimized maps of groundwater table depths and nitrate concentrations using geospatial models, based on 123 data points for groundwater levels and 71 data points for nitrate concentrations. Empirical Bayesian Kriging (EBK) proved to be the most effective interpolation technique for groundwater table depth, while Simple Kriging (SK) was the best choice for predicting nitrate concentration, as determined by the lowest root mean square error (RMSE). The ranking of interpolation models for groundwater table depths was EBK > SK > OK > UK > IDW > RBF > LPI, whereas for nitrate concentrations, the models ranked as SK > EBK > IDW > OK > UK > RBF > LPI. These results demonstrate that geostatistical methods outperformed deterministic interpolation techniques for both parameters. The northwest and central regions of the study area were found to have shallow groundwater table depths, areas that also exhibited high nitrate concentrations, likely due to their proximity to pollutant sources. This research provides valuable insights for promoting sustainable groundwater exploration and implementing effective measures to protect groundwater from contamination.

Field experiment was conducted during 2012/13 and 2013/14 cropping season at Kafta Humera to evaluate sesame response to Urea and Ammonium sulfate. Treatments were: 0, 41 N from urea+20P, 20 N from Urea + 21 N from NH₄SO₄ [24 S] +20P and, 41 N from NH₄SO₄ [47 S] +20P were applied at five farmers' field with two replications. The initial soil analysis revealed that strong alkaline, low organic matter and Nitrogen while very low in available phosphorus and sulfur, high CEC with clay texture. The agronomic parameters like 50% Flowering, days to 50% Maturity, plant height, Length of pod-bearing zone, Number of capsule per plant, Number of seeds per Capsule and grain yield were significantly (P < 0.05) affected by treatments. treatments received 20 N from Urea + 21 N from NH4SO4 [24 S]+20P followed by 41 N from urea+20P obtained additional grain yield (148.1% & 85%), number of capsules per plant (79.5% & 56.5%), plant height (60.7% & 31.7%), Branch number (62.7% & 28.7%) over the control, respectively. While the length of pod-bearing zone was significantly affected due to only 20 N from Urea + 21 N from NH4SO4 [24 S] +20P. This study implies that sulfur, Nitrogen and phosphorus in the area are deficient nutrients that limit Sesame crop production. Hence, a combined application of urea and ammonium sulfate as the sources for nitrogen and sulfur with phosphorus is best to enhance sesame crop production on Vertisols of Kafta Humera.

Due to the ever-increasing demand for water in Aynalem catchment and its surrounding, there has been an increased pressure on the Aynalem well field putting the sustainability of water supply from the aquifer under continuous threat. Thus, it is vital to understand the water balance of the catchment to ensure sustainable utilization of the groundwater resource. This in turn requires proper quantification of the components of water balance among which recharge estimation is the most important. This paper estimates the groundwater recharge of the Aynalem catchment using high-resolution hydro-meteorological data. Daily precipitation and temperature measurement data for years 2001-2018; groundwater level fluctuation records collected at every 30 minutes; and soil and land use maps were used to make recharge estimations. In the groundwater level fluctuation, three boreholes were monitored, but only two were utilized for the analysis because the third was under operation and does not represent the natural hydrologic condition. Thornthwaite soil moisture balance and groundwater level fluctuation methods were applied to determine the groundwater recharge of the Aynalem catchment. Accordingly, the annual rate of groundwater recharge estimated based on the soil-water balance ranges between 7mm/year and 138.5 mm/year with the weighted average value of 89.04 mm/year. The weighted average value is considered to represent the catchment value because the diverse soil and land use/cover types respond differently to allow the precipitation to recharge the groundwater. On the other hand, the groundwater recharge estimated using the groundwater level fluctuation method showed yearly groundwater recharge of 91 to 93 mm/year. The similarity in the groundwater recharge result obtained from both methods strengthens the acceptability of the estimate. It also points out that the previously reported estimate is much lower (36 to 66 mm/year).

A field experiment was carried out during 2012/2013 on acidic soil of Tsegede highlands, Northern Ethiopia to evaluate wheat crop response to different Fertilizers and Liming with four treatments: (1) (No fertilizer), (2) 64 kg/ha Nitrogen+ 150 kg/ha Minjingu organic hyper phosphate fertilizer, (3) 64 kg/ha Nitrogen and 20 kg/ha Phosphorus, and (4) 64 kg/ha Nitrogen and 20 kg/ha Phosphorus + 4.17 t/ha lime were arranged in Randomized Complete Block Design (RCBD) deign with three replications. Soil samples were collected before planting and analyzed for selected physicochemical properties, which revealed that textural class was sandy loam and the pH, Exchangeable aluminum and Exchangeable Acid as very strong acid and toxic for plant growth. The total percentage of organic matter, Nitrogen and Cation Exchange capacity (CEC) were as high; while very low in available phosphorus. Results indicated soil that received 64 kg/ha Nitrogen from urea+150 kg/ha Minjingu organic hyper phosphate, 64 kg/ha Nitrogen and 20 Phosphorus and 64 kg/ha Nitrogen and 20 kg/ha Phosphorus + 4.17 t/ha lime gave additional grain yield increment by about 191, 211 and 413% over the control, respectively. While the straw yield improved by 226, 248 and 422% respectively. The highest yield was recorded on soils with 64 kg/ha Nitrogen and 20 kg/ha Phosphorus along with lime followed by the 64 kg/ha Nitrogen and 20 kg/ha Phosphorus, and soil with application of 64 kg/ha Nitrogen from urea+150 kg/ha Minjingu organic hyper phosphate. The recorded plant height was significantly affected only at 64 kg/ha Nitrogen and 20 kg/ha Phosphorus + 4.17 t/ha lime (21.2%) over the control. Hence uncontrolled land encroachment in the low land areas can minimize to make these farmlands productive. The rate of these fertilizers and marginal rate of return was not studied. Key words: HAR-604, lime, Minjingu organic hyper phosphate, nitrogen, phosphorus.