scholarly journals PERFORMANCE EVALUATION OF IRRIGATION SCHEMES IN RUGERAMIGOZI MARSHLAND, RWANDA

2020 ◽  
Vol 4 (1) ◽  
pp. 15-19
Author(s):  
Janvier Hakuzimana ◽  
Blessing Masasi

Evaluating irrigation schemes contributes to the identification of performance gaps and this may lead to implementation of necessary improvements for enhancing agricultural productivity. In Rwanda, despite significant investments in irrigated agriculture, most of the irrigation schemes are performing far below their planned capacity. This study aimed at benchmarking the performance of Rugeramigozi 1 and Rugeramigozi 2 irrigation schemes located in Rugeramigozi marshland, Rwanda using irrigation indicators developed by the International Water Management Institute (IWMI). The study showed that land productivity for both the two irrigation schemes was generally low. Rugeramigozi 2 irrigation scheme had superior performance than Rugeramigozi 1 in terms of water productivity due to adoption of deficit irrigation strategies that promoted water conservation. The performance indicators for water service delivery showed that water use was more sufficient in Rugeramigozi 1 compared to Rugeramigozi 2 irrigation scheme. The water delivery capacity performance for both schemes revealed that the existing irrigation canals were sufficient to meet the irrigation water requirements at peak demand. The analysis of financial performance in both schemes indicated that the collected irrigation fees were inadequate to cover the operation and maintenance costs. Similarly, the gross returns on investment were low in both irrigation schemes due to low crop yields that generated low revenue for farmers. Overall, the performance indicators showed that both Rugeramigozi 1 and Rugeramigozi 2 irrigation schemes were in need of intensive management and infrastructural improvements in order to increase productivity and enhance sustainability of the schemes.

2015 ◽  
Vol 76 (15) ◽  
Author(s):  
Umar Mohammed ◽  
Aimrun Wayayok ◽  
Mohd Amin Mohd Soom ◽  
Khalina Abdan

Weed emergence is among the most important problems in system of rice intensification (SRI) due to extensive planting geometry of at least 25 × 25 cm and moist environment, thereby leading to water loss by means of evaporation from the broad space as a result of the extensive planting geometry, and transpiration by the weeds. This reduces the additional water saving which affect the potential of SRI water productivity.  It also reduces rice crop yields up to 70% if there is no weed control attempted. Nowadays, weed is being controlled by manual weeder which is labour demanding, while motorized weeders overcome the problem but still, it able to remove the weeds before rice canopy closure or 30 days after transplanting (DAT). This research was designed to evaluate the performance of UMAR-SRImat on soil moisture conservation and weed control. UMAR-SRImat was made using flaked rice straw and biodegradable adhesive. The design was laid out using randomized complete block design (RCBD) with three treatments [without soil cover (T1), SRImat (T2), UMAR-SRImat (T3)] and three replications. The analysis was conducted using analysis of variance (ANOVA). Volumetric moisture content (VMC) was determined at 18 and 25 DAT.  Weeds were observed and recorded to determine the weed dry weight and weed control efficiency at 20, 40 and 60 DAT. Plant height per hill was measured at 30 and 50 DAT, likewise, the number of tillers were counted at 30 and 50 DAT. The result of VMC showed that UMAR-SRImat significantly conserved water higher than the control treatment at 18 and 25 DAT of 3100.0a and 2680.0a m3/ha, respectively. The effectiveness of UMAR-SRImat mulched was 100% at 20 DAT 99.64% at 40 DAT and 97.99% at 60 DAT. This research revealed that UMAR-SRImat mulch could retain soil moisture and suppressed weeds up to 60 DAT.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingwen Zhang ◽  
Kaiyu Guan ◽  
Bin Peng ◽  
Ming Pan ◽  
Wang Zhou ◽  
...  

AbstractIrrigation is an important adaptation to reduce crop yield loss due to water stress from both soil water deficit (low soil moisture) and atmospheric aridity (high vapor pressure deficit, VPD). Traditionally, irrigation has primarily focused on soil water deficit. Observational evidence demonstrates that stomatal conductance is co-regulated by soil moisture and VPD from water supply and demand aspects. Here we use a validated hydraulically-driven ecosystem model to reproduce the co-regulation pattern. Specifically, we propose a plant-centric irrigation scheme considering water supply-demand dynamics (SDD), and compare it with soil-moisture-based irrigation scheme (management allowable depletion, MAD) for continuous maize cropping systems in Nebraska, United States. We find that, under current climate conditions, the plant-centric SDD irrigation scheme combining soil moisture and VPD, could significantly reduce irrigation water use (−24.0%) while maintaining crop yields, and increase economic profits (+11.2%) and irrigation water productivity (+25.2%) compared with MAD, thus SDD could significantly improve water sustainability.


2012 ◽  
Vol 9 (11) ◽  
pp. 12921-12958 ◽  
Author(s):  
P. Karimi ◽  
W. G. M. Bastiaanssen ◽  
D. Molden ◽  
M. J. M. Cheema

Abstract. The paper describes the application of a new Water Accounting Plus (WA+) framework to produce spatial information on water flows, sinks, uses, storages and assets, in the Indus Basin, South Asia. It demonstrates how satellite-derived estimates of land use, land cover, rainfall, evaporation (E), transpiration (T), interception (I) and biomass production can be used in the context of WA+. The results for one selected year showed that total annual water depletion in the basin (502 km3) plus outflows (21 km3) exceeded total precipitation (482 km3). The deficit in supply was augmented through abstractions beyond actual capacity, mainly from groundwater storage (30 km3). The "landscape ET" (depletion directly from rainfall) was 344 km3 (69% of total consumption). "Blue water" depletion ("utilized flow") was 158 km3 (31%). Agriculture was the biggest water consumer and accounted for 59% of the total depletion (297 km3), of which 85% (254 km3) was through irrigated agriculture and the remaining 15% (44 km3) through rainfed systems. While the estimated basin irrigation efficiency was 0.84, due to excessive evaporative losses in agricultural areas, half of all water consumption in the basin was non-beneficial. Average rainfed crop yields were 0.9 t ha−1 and 7.8 t ha−1 for two irrigated crop growing seasons combined. Water productivity was low due to a lack of proper agronomical practices and poor farm water management. The paper concludes that the opportunity for a food-secured and sustainable future for the Indus Basin lies in focusing on reducing soil evaporation. Results of future scenario analyses suggest that by implementing techniques to convert soil evaporation to crop transpiration will not only increase production but can also result in significant water savings that would ease the pressure on the fast declining storage.


Author(s):  

Under the semiarid and arid climate of Eastern Europe, accurate estimation of crop water requirement and irrigation scheduling is important for water management and planning. The objectives of this study were to estimate maize water requirement and irrigation scheduling in variable climatic conditions. CROPWAT model is decision support system developed by United Nations Food and Agriculture Organization (FAO) and it is used as a practical tool to carry out standard calculations for reference evapotranspiration, crop water requirements, irrigation scheduling, and also allows helps in planning and decision making in the areas where water resource availability is varying and scarce. The study result indicated that Maize seasonal amounts of irrigation requirements varied from 439.5 to 615.0 mm. Maize actual daily evapotranspiration (ETa) varied from 0.12 to 4.13 mm and from 0.27 to 4.68 mm in 2010 and 2011 respectively. Net irrigation schedule for all growing periods in 2010 was zero for initial and late but for development 138.9 mm and 45.9 mm for mid-stage of the growing period. However, 2011 were zero, 83.7 mm, 178 mm, and 98.2 mm in initial, mid, and development and late stages respectively. Besides in the study area, 2010 was the wettest year but 2011 was determined as the driest year this may cause adverse conditions on maize crop yields quantity and quality. Irrigation requirements for maize should be adjusted to the local meteorological conditions for optimizing maize irrigation requirements and improving maize water productivity under such climatic variable conditions.


Author(s):  
Mireia Fontanet ◽  
Daniel Fernàndez-Garcia ◽  
Gema Rodrigo ◽  
Francesc Ferrer ◽  
Josep Maria Villar

AbstractIn the context of growing evidence of climate change and the fact that agriculture uses about 70% of all the water available for irrigation in semi-arid areas, there is an increasing probability of water scarcity scenarios. Water irrigation optimization is, therefore, one of the main goals of researchers and stakeholders involved in irrigated agriculture. Irrigation scheduling is often conducted based on simple water requirement calculations without accounting for the strong link between water movement in the root zone, soil–water–crop productivity and irrigation expenses. In this work, we present a combined simulation and optimization framework aimed at estimating irrigation parameters that maximize the crop net margin. The simulation component couples the movement of water in a variably saturated porous media driven by irrigation with crop water uptake and crop yields. The optimization component assures maximum gain with minimum cost of crop production during a growing season. An application of the method demonstrates that an optimal solution exists and substantially differs from traditional methods. In contrast to traditional methods, results show that the optimal irrigation scheduling solution prevents water logging and provides a more constant value of water content during the entire growing season within the root zone. As a result, in this case, the crop net margin cost exhibits a substantial increase with respect to the traditional method. The optimal irrigation scheduling solution is also shown to strongly depend on the particular soil hydraulic properties of the given field site.


1980 ◽  
Vol 7 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D. L. Hallock ◽  
A. H. Allison

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.


2020 ◽  
Vol 69 (S1) ◽  
pp. 23-37
Author(s):  
Solomon Habtu ◽  
Teklu Erkossa ◽  
Jochen Froebrich ◽  
Filmon Tquabo ◽  
Degol Fissehaye ◽  
...  

Utafiti ◽  
2015 ◽  
Vol 11 (1-2) ◽  
pp. 33-66
Author(s):  
Onesmo Selijio

Land management and conservation have been considered the most important aspects of sustainable productivity in economically developing countries where land degradation is a major challenge. In Tanzania, both the government and international organizations have been promoting adoption of land management and conservation technologies (LMCTs) for a long time. This paper establishes the impact of three LMCTs – soil water conservation technologies and erosion control (SWCEC), organic and inorganic fertilizers – on maize crop yields in different rainfall zones, using national panel survey data. The study employs static panel models to analyse the two-period data sets for 2008-2009 and 2010-2011. The results indicate that adoption of LMCTs do contribute significantly to maize yield. The greatest effects of organic and SWCEC methods on crop yield were realized in low rainfall zones, while that of inorganic fertilizers was observed in high rainfall zones. These findings support previous cross-sectional data analyses, suggesting for policy makers that a blanket land management and conservation programme applied uniformly to all agro-ecological zones is not strategically beneficial. The advisability of a technology employed in a given zone should be supported by local knowledge and research findings culled from that particular area.


2015 ◽  
Vol 19 (7) ◽  
pp. 3073-3091 ◽  
Author(s):  
J. Jägermeyr ◽  
D. Gerten ◽  
J. Heinke ◽  
S. Schaphoff ◽  
M. Kummu ◽  
...  

Abstract. Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatiotemporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of global agricultural water use, and of water saving and water productivity potentials constrained by biophysical processes and also non-trivial downstream effects, we incorporated a process-based representation of the three major irrigation systems (surface, sprinkler, and drip) into a bio- and agrosphere model, LPJmL. Based on this enhanced model we provide a gridded world map of irrigation efficiencies that are calculated in direct linkage to differences in system types, crop types, climatic and hydrologic conditions, and overall crop management. We find pronounced regional patterns in beneficial irrigation efficiency (a refined irrigation efficiency indicator accounting for crop-productive water consumption only), due to differences in these features, with the lowest values (< 30 %) in south Asia and sub-Saharan Africa and the highest values (> 60 %) in Europe and North America. We arrive at an estimate of global irrigation water withdrawal of 2469 km3 (2004–2009 average); irrigation water consumption is calculated to be 1257 km3, of which 608 km3 are non-beneficially consumed, i.e., lost through evaporation, interception, and conveyance. Replacing surface systems by sprinkler or drip systems could, on average across the world's river basins, reduce the non-beneficial consumption at river basin level by 54 and 76 %, respectively, while maintaining the current level of crop yields. Accordingly, crop water productivity would increase by 9 and 15 %, respectively, and by much more in specific regions such as in the Indus basin. This study significantly advances the global quantification of irrigation systems while providing a framework for assessing potential future transitions in these systems. In this paper, presented opportunities associated with irrigation improvements are significant and suggest that they should be considered an important means on the way to sustainable food security.


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