scholarly journals A Review on Managing Agroecosystems for Improved Water Use Efficiency in the Face of Changing Climate in Tanzania

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jerome Kimaro

Agroecosystems are important for food production and conservation of biodiversity while continuing to provide several ecosystem services within the landscape. Despite their economic and ecological benefits, most agroecosystems in Tanzania are degraded at alarming rates. Rapid increase of human population and unprecedented impacts of climate change have influenced depletion of natural resource base within agroecosystem in recent decades compared to what communities have experienced before. Increased food demands owing to population increase have increased pressure on exploitation of land resources including water. Cultivation area and irrigation water demands have increased steadily in the last six decades. Nevertheless, approaches used for water supply have not been improved; thus, water use efficiency in most irrigation schemes is quite poor. Conversely, climate smart agricultural practices are practiced less in Tanzania. There is poor adoption of recommended adaptation among smallholder farmers due to several socioeconomic reasons. One of the key objectives of climate smart agriculture is to improve bio-geochemical interactions within landscape and decrease competition of natural resources between humans and other component of agroecosystems. This underscores the assumptions that most cropping systems in Tanzania are not managed sustainably. Moreover, comprehensive assessment of hydrological dynamics within smallholder farming in Tanzania is highly lacking. Therefore, actual causes and extent of water resources depletion are largely unknown among stakeholders. In most tropical landscapes, water resources degradation is influenced by interaction of both anthropogenic and biophysical factors operating at different times and space scales. As the capacity of water-supplying sources continues to decline, Tanzania needs profound changes in agricultural production systems in order to nourish the growing human population. This calls for strategic approaches that have wider adaptability. A literature survey study with the following objectives was conducted (i) to assess current state of agricultural water use and irrigation activities in Tanzania and (ii) to determine major constraints for sustainable water management and identify appropriate adaptation measures for their improvement across diverse cropping systems.

2013 ◽  
Vol 409-410 ◽  
pp. 79-82 ◽  
Author(s):  
Ying Qin Chen ◽  
Xian Feng Huang

Due to the rich resources of urban rainwater and transit flood in coastal areas, rational utilization of rainfall and flood water resources can improve the sustainable utilization, to better serve the coastal development. In this paper, the available quantity of water rainfall and flood water resources in coastal are distributed to domestic water, industrial water, agricultural water and ecologic environmental water. Water price method is used to calculate domestic water efficiency. Energy synthesis is used to calculate the industrial and agricultural water-use efficiency. Ecologic environmental water-use efficiency-sharing coefficient method is used to calculate the ecologic environmental water-use efficiency. Finally, taking Lianyungang City, a Jiangsu coastal city as an example to analyze the rainfall and flood water resources utilization efficiency. The results provide reference to the research for Chinas plain area rainfall and flood water resources efficiency analysis.


2016 ◽  
Vol 74 (5) ◽  
pp. 1106-1115 ◽  
Author(s):  
L. Mu ◽  
L. Fang ◽  
H. Wang ◽  
L. Chen ◽  
Y. Yang ◽  
...  

Worldwide, water scarcity threatens delivery of water to urban centers. Increasing water use efficiency (WUE) is often recommended to reduce water demand, especially in water-scarce areas. In this paper, agricultural water use efficiency (AWUE) is examined using the super-efficient data envelopment analysis (DEA) approach in Xi'an in Northwest China at a temporal and spatial level. The grey systems analysis technique was then adopted to identify the factors that influenced the efficiency differentials under the shortage of water resources. From the perspective of temporal scales, the AWUE increased year by year during 2004–2012, and the highest (2.05) was obtained in 2009. Additionally, the AWUE was the best in the urban area at the spatial scale. Moreover, the key influencing factors of the AWUE are the financial situations and agricultural water-saving technology. Finally, we identified several knowledge gaps and proposed water-saving strategies for increasing AWUE and reducing its water demand by: (1) improving irrigation practices (timing and amounts) based on compatible water-saving techniques; (2) maximizing regional WUE by managing water resources and allocation at regional scales as well as enhancing coordination among Chinese water governance institutes.


2014 ◽  
Vol 50 (4) ◽  
pp. 549-572 ◽  
Author(s):  
V. S. RATHORE ◽  
N. S. NATHAWAT ◽  
B. MEEL ◽  
B. M. YADAV ◽  
J. P. SINGH

SUMMARYThe choice of an appropriate cropping system is critical to maintaining or enhancing agricultural sustainability. Yield, profitability and water use efficiency are important factors for determining suitability of cropping systems in hot arid region. In a two-year field experiment (2009/10–2010/11) on loam sandy soils of Bikaner, India, the production potential, profitability and water use efficiency (WUE) of five cropping systems (groundnut–wheat, groundnut–isabgol, groundnut–chickpea, cluster bean–wheat and mung bean–wheat) each at six nutrient application rate (NAR) i.e. 0, 25, 50, 75, 100% recommended dose of N and P (NP) and 100% NP + S were evaluated. The cropping systems varied significantly in terms of productivity, profitability and WUEs. Averaged across nutrient application regimes, groundnut–wheat rotation gave 300–1620 kg ha−1 and 957–3365 kg ha−1 higher grain and biomass yields, respectively, than other cropping systems. The mean annual net returns were highest for the mung bean–wheat system, which returned 32–57% higher net return than other cropping systems. The mung bean–wheat and cluster bean–wheat systems had higher WUE in terms of yields than other cropping systems. The mung bean–wheat system recorded 35–63% higher WUE in monetary terms compared with other systems. Nutrients application improved yields, profit and WUEs of cropping systems. Averaged across years and cropping systems, the application of 100% NP improved grain yields, returns and WUE by 1.7, 3.9 and 1.6 times than no application of nutrients. The results suggest that the profitability and WUEs of crop production in this hot arid environment can be improved, compared with groundnut–wheat cropping, by substituting groundnut by mung bean and nutrients application.


2016 ◽  
Vol 13 (2) ◽  
pp. 94-107 ◽  
Author(s):  
S Roy ◽  
M Barman ◽  
AM Puste ◽  
SK Gunri ◽  
K Jana

Field experiment was conducted at Instructional Farm, Jaguli (Mohanpur), Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India during two consecutive summer seasons of 2010-11, and 2011-12. The experiment was laid out in split-plot design having 4 levels of irrigation– rainfed without mulch, rainfed with mulch, irrigation at IW (depth of irrigation water) / CPE (Cumulative pan evaporation) ratios of 0.5 and 0.75 in main-plot and 4 inter cropping systems, sole maize, sole mungbean, maize + mungbean (1:1 row ratio) and maize + mungbean (3:2 row ratio) considered as sub-plot treatments replicated thrice. Results revealed that application of irrigation and intercropping systems markedly influenced the growth, yield and yield components (number of cobs/plant, number of grains/cob in case of maize and number of pods/plant and number of seeds/pod in case of mungbean) where the maximum value of these components were recorded with the application of irrigation at IW/CPE ratio 0.75 in sole crop. Maize-mungbean in 3:2 row ratio yielded higher than that of 1:1 intercropping system which might be due to less light interception and more competition for water and nutrition between both the crops. CU of water increased with the increasing levels of irrigation and the maximum value (17.75 kg ha-1 mm- 1) of WUE (water use efficiency) was observed with irrigation at IW: CPE ratio 0.75 under intercropping system of maize : mungbean in 3:2 row ratio followed by IW: CPE ratio 0.50. Among the sole crop, maximum WUE was with IW/CPE ratio 0.75 might be due to more consumption of water corresponding to production potential of maize, while, it was more under rainfed with mulch in mungbean. The relative crowding coefficient (RCC) also revealed both the intercropping systems were advantageous and the land equivalent ratio (LER) increased with the level of irrigation.Thus, maize grown in association with mungbean (3:2 row ratio) were found to be more profitable (B:C ratio of 2.58) with higher monetary advantage as compared to sole crop of maize (B:C ratio of 1.98) with the application of irrigation at IW: CPE ratio of 0.75 in new alluvial zone of West Bengal.SAARC J. Agri., 13(2): 94-107 (2015)


2019 ◽  
Vol 21 (3) ◽  
pp. 381-396 ◽  
Author(s):  
Kun Cheng ◽  
Shuai Wei ◽  
Qiang Fu ◽  
Wei Pei ◽  
Tianxiao Li

Abstract Adaptive management is currently an important method to optimize the management of complex water resources systems. Regional water resources adaptive management was conducted based on the advanced theory of a complex system multi-agent model; the state of an agent was tracked and modified by information entropy theory, which was improved by using individual standard deviations. With the goal of optimizing the adaptation of each agent of the region, water resources in the major grain production area of China were managed under the constraints of the total annual available water resources and water use efficiency requirements for 2015 and 2030. By introducing the adaptive water resources management in 2015, the domestic benefits and economic benefits increased by 2.90% and 14.81%, respectively, with respect to observed values. The ecological benefits declined by 3.63%, but ecological water demand was fully satisfied, and the ecological water environment was improved. Given the water use efficiency targets in 2030, applying adaptive management resulted in an increase of domestic, economic, and ecological benefits of 34.29%, 21.14%, and 1.78%, respectively. The results show that the adaptive management method presented can help managers to balance the benefits of various agents to determine the direction of water resources management decisions.


2017 ◽  
Vol 35 (1) ◽  
pp. 275-280
Author(s):  
Hossein Yousefi ◽  
Ali Mohammadi ◽  
Mitra Mirzaaghabeik ◽  
Younes Noorollahi

AbstractShortage of water is considered as one of the most important straits of agricultural development in Iran. The main purpose of this study is to determine virtual water used to pea and bean production and water use efficiency, select the best area for cultivating these two grains and find the virtual water budget for the aforementioned grains. The results showed that among the three provinces main producers of pea in Iran, the highest virtual water of pea belongs to Lorestan with 3534 dm3·kg−1 and the lowest belongs to West Azerbaijan with 2660 dm3·kg−1 in irrigated cultivation. Water use efficiency in irrigated cultivation in Kermanshah and West Azerbaijan are at the same level; however, Kermanshah has enjoyed much more level of virtual water. For beans, the highest amount of virtual water in irrigated cultivation belongs to Lorestan (3651 dm3·kg−1) and the lowest amount refers to Markazi (2725 dm3·kg−1) and also the highest level of water use efficiency for this product refers to Markazi. Also it was found that 160.15 mln m3 of water has been exported from the country water resources by these products so virtual water budget for studied crops were negative.


Author(s):  
Wen-Jie Xu ◽  
Xiao-Ping Zhang ◽  
Qian Xu ◽  
Hui-Ling Gong ◽  
Qing Li ◽  
...  

In order to realize the sustainable utilization of water resources and the sustainable development of economy, the evaluation index system of water use efficiency system and economic development system was constructed. Entropy weight method and comprehensive evaluation method were adopted to determine the index weights and conduct comprehensive evaluation for the two systems. The coupling coordination model was used to calculate the coupling degree, coordination degree and coupling coordination degree of the two systems. The annual coupling stage and coupling coordination intensity of the two systems were analyzed and determined. The results showed that the comprehensive evaluation values of both water use efficiency system and economic development system in Jinan City increased greatly from 2008 to 2017, and showed a changing trend of ups and downs. The two systems were in the antagonistic stage, and were gradually approaching the running-in stage, indicating that they were in the state of common development. The coupling coordination degree of the two systems gradually increased in waves, progressed from the moderately to the highly coordinated coupling. In the future, if the water control path appropriate to Jinan City can be explored actively, the water-saving kinetic energy of economic development can be increased constantly, and the linkage effect between economic development and water resources utilization can be given full play to, the two systems will be in the orbit with the benign interaction and healthy harmonious development.


2018 ◽  
Vol 8 ◽  
Author(s):  
Alexandra Tomaz ◽  
Manuel Patanita ◽  
Isabel Guerreiro ◽  
José Dôres ◽  
Luis Boteta ◽  
...  

In the region of Alentejo, Southern Portugal, as a consequence of the implementation of the Alqueva global irrigation system, agriculture intensification is challenging the sustainability of the farming systems. The demand for water and for fertilizers is increasing but so is the demand for water use efficiency (WUE) and for nutrient use efficiency (NUE). Increasing resource-use efficiency while reducing yield gaps can be addressed by suitable agricultural management practices, as in the case of crop rotations. Based on a demonstration project carried out in two farms located in Baixo Alentejo, within the Alqueva irrigation network, soil fertility parameters, WUE and NUE (for nitrogen, phosphorus and potassium) were studied in three maize-based cropping systems: a maize monoculture (M-M) and two rotations, barley+maize-barley (BM-B) and sunflower-barley+maize (S-BM). The total soil organic matter content increased in the two rotations, an important observation especially in soils with low organic content. The final balance of extractable phosphorus and potassium was positive in the BM-B rotation. Water use efficiency values point to a less balanced performance of the S-BM rotation. The WUE and the nitrogen NUE in the different crops and rotations followed a similar pattern. The M-M and BM-B crop successions showed the best indicators of NUE for nitrogen and phosphorus. In all the cropping systems, the potassium NUE was low, suggesting the need to carefully equate the additions of this nutrient by fertilization.


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