Work on improvement of saline-alkali land on the University Farm, Khartoum, 1956–59

1961 ◽  
Vol 57 (3) ◽  
pp. 367-371
Author(s):  
G. A. Worrall
Keyword(s):  
Irrigation Water ◽  
Detrimental Effect ◽  
Crop Yields ◽  
Salt Content ◽  
Upward Movement ◽  
Water Penetration ◽  
Steady Improvement ◽  
General Improvement ◽  
The University ◽  
Original Amount

Over the 3 years of the experiment the salt in the top 2 ft. of the soil was reduced by almost a half of the original amount, and nearly all this was removed in the first season. The movement was downwards, and there was little evidence of any upward movement; flushing was not very effective in removing salt from the soil. The type of cultivation affected the amount of salt removed, deep subsoiling being most successful with over 50% removal, but irrigation without any cultivation removed 29%. The penetration of irrigation water was very restricted in the first waterings, but became increasingly deeper as the experiment continued.Crop yields showed a steady improvement from season to season, the final average of about 1500 lb. per feddan being above the average for the district. The various treatments did not appear to have much effect on the yields, and the general improvement in yields is attributed to the reduction of salt content and to the deeper water penetration, chiefly the latter. The detrimental effect of the dry north winds was more apparent than the effects of the different treatments.

scholarly journals A field-validated surrogate crop model for predicting root-zone moisture and salt content in regions with shallow groundwater

2020 ◽  
Vol 24 (8) ◽  
pp. 4213-4237 ◽  
Author(s):  
Zhongyi Liu ◽  
Zailin Huo ◽  
Chaozi Wang ◽  
Limin Zhang ◽  
Xianghao Wang ◽  
...  
Keyword(s):  
Field Experiment ◽  
Irrigation Water ◽  
Salt Content ◽  
Shallow Groundwater ◽  
Crop Growth ◽  
Groundwater Depth ◽  
Upward Movement ◽  
Area Index ◽  
Calibration And Validation ◽  
Irrigated Crops

Abstract. Optimum management of irrigated crops in regions with shallow saline groundwater requires a careful balance between application of irrigation water and upward movement of salinity from the groundwater. Few field-validated surrogate models are available to aid in the management of irrigation water under shallow groundwater conditions. The objective of this research is to develop a model that can aid in the management using a minimum of input data that are field validated. In this paper a 2-year field experiment was carried out in the Hetao irrigation district in Inner Mongolia, China, and a physically based integrated surrogate model for arid irrigated areas with shallow groundwater was developed and validated with the collected field data. The integrated model that links crop growth with available water and salinity in the vadose zone is called Evaluation of the Performance of Irrigated Crops and Soils (EPICS). EPICS recognizes that field capacity is reached when the matric potential is equal to the height above the groundwater table and thus not by a limiting hydraulic conductivity. In the field experiment, soil moisture contents and soil salt conductivity at five depths in the top 100 cm, groundwater depth, crop height, and leaf area index were measured in 2017 and 2018. The field results were used for calibration and validation of EPICS. Simulated and observed data fitted generally well during both calibration and validation. The EPICS model that can predict crop growth, soil water, groundwater depth, and soil salinity can aid in optimizing water management in irrigation districts with shallow aquifers.

scholarly journals Assessing biogeochemical effects and best management practice for a wheat–maize cropping system using the DNDC model

2014 ◽  
Vol 11 (1) ◽  
pp. 91-107 ◽  
Author(s):  
F. Cui ◽  
X. Zheng ◽  
C. Liu ◽  
K. Wang ◽  
Z. Zhou ◽  
...  
Keyword(s):  
Nitrate Leaching ◽  
Irrigation Water ◽  
Crop Yields ◽  
Management Practice ◽  
Best Management Practice ◽  
Nitrification Inhibitors ◽  
Nh3 Volatilization ◽  
Dndc Model ◽  
Best Management ◽  
Management Alternatives

Abstract. Contemporary agriculture is shifting from a single-goal to a multi-goal strategy, which in turn requires choosing best management practice (BMP) based on an assessment of the biogeochemical effects of management alternatives. The bottleneck is the capacity of predicting the simultaneous effects of different management practice scenarios on multiple goals and choosing BMP among scenarios. The denitrification–decomposition (DNDC) model may provide an opportunity to solve this problem. We validated the DNDC model (version 95) using the observations of soil moisture and temperature, crop yields, aboveground biomass and fluxes of net ecosystem exchange of carbon dioxide, methane, nitrous oxide (N2O), nitric oxide (NO) and ammonia (NH3) from a wheat–maize cropping site in northern China. The model performed well for these variables. Then we used this model to simulate the effects of management practices on the goal variables of crop yields, NO emission, nitrate leaching, NH3 volatilization and net emission of greenhouse gases in the ecosystem (NEGE). Results showed that no-till and straw-incorporated practices had beneficial effects on crop yields and NEGE. Use of nitrification inhibitors decreased nitrate leaching and N2O and NO emissions, but they significantly increased NH3 volatilization. Irrigation based on crop demand significantly increased crop yield and decreased nitrate leaching and NH3 volatilization. Crop yields were hardly decreased if nitrogen dose was reduced by 15% or irrigation water amount was reduced by 25%. Two methods were used to identify BMP and resulted in the same BMP, which adopted the current crop cultivar, field operation schedules and full straw incorporation and applied nitrogen and irrigation water at 15 and 25% lower rates, respectively, than the current use. Our study indicates that the DNDC model can be used as a tool to assess biogeochemical effects of management alternatives and identify BMP.

scholarly journals Water savings potentials of irrigation systems: global simulation of processes and linkages

2015 ◽  
Vol 19 (7) ◽  
pp. 3073-3091 ◽  
Author(s):  
J. Jägermeyr ◽  
D. Gerten ◽  
J. Heinke ◽  
S. Schaphoff ◽  
M. Kummu ◽  
...  
Keyword(s):  
Water Consumption ◽  
Irrigation Water ◽  
Crop Yields ◽  
Water Productivity ◽  
Irrigation Efficiency ◽  
Sub Saharan Africa ◽  
Water Withdrawal ◽  
Indus Basin ◽  
Irrigation Systems ◽  
Regional Patterns

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.

scholarly journals SUBSTANTIATION OF CHOICE OF VEGETABLE CROPS SUITABLE FOR GROWING ON SALTED SOILS

2020 ◽  
Vol 5 (4(73)) ◽  
pp. 12-18
Author(s):  
G.T. Bekmirzaev ◽  
I.A. Begmatov ◽  
D.B. Yulchiev
Keyword(s):  
Experimental Study ◽  
New Zealand ◽  
Salt Content ◽  
Vegetable Crops ◽  
Agricultural Systems ◽  
Salt Tolerant ◽  
As Species ◽  
High Salt Content ◽  
The University ◽  
Selection Of

The purpose of the experimental study was the selection of salt tolerant crops and the search for useful horticultural species for growing them on saline lands. The experimental study was conducted at the University of Algarve, Portugal, in a greenhouse. The following vegetable crops were selected for research: lettuce (Lactuca sativaL), New Zealand spinach (Tetragonia tetragonioides) and garden purslane (Portulaca oleracea). Experimental results showed that New Zealand spinach and garden purslane have high potential as species resistant to high salt content and are therefore recommended for cultivation in order to reduce soil salinity. The above crops, mainly New Zealandspinach, are good types of garden crops with high useful qualities and productivity. Therefore, it has been shown that this method is a clean and environmentally friendly tool to prevent salinization and maintain the sustainability of agricultural systems

scholarly journals The Response of Fordhook Giant / Swisschard (Beta vulgaris var Cicla) and Mustard (Brassica Juncea) Spinach Vegetables to Irrigation with Saline Water

2020 ◽  
pp. 20-26
Author(s):  
M. V. Dlamini ◽  
M. T. Masarirambi
Keyword(s):  
Plant Height ◽  
Irrigation Water ◽  
Saline Water ◽  
Block Design ◽  
Water Source ◽  
Saline Irrigation ◽  
Randomized Block Design ◽  
Salinity Levels ◽  
Number Of Leaves ◽  
The University

Saline irrigation water is becoming an important water source as fresh water is fast becoming a scarce resource in many areas of the world, including Eswatini, especially in arid and semi-arid regions.  A study to test the response of two varieties of spinach (fordhook giant and mustard) to salinity was conducted in a field pot experiment at the Faculty of Agriculture at the Luyengo Campus of the University of Eswatini.  The treatments were laid in a randomized block design (RCBD).  The experiment consisted of four treatments, each replicated twelve times.  Treatments were salinity levels of 0.0 dS/m, 1.5 dS/m, 2.0 dS/m and 3.5 dS/m.  All the treatments were subjected to similar agronomic practices. Spinach was grown and observed for a period of five weeks.  Plant height was measured and the number of leaves counted weekly throughout the experiment. Significant differences (P < 0.05) between salinity treatments were obtained for plant height beginning in week 2 but were more pronounced in week 3, 4 and week 5.  No significant differences were obtained for the number of leaves.  There were however, clear significant differences between spinach irrigated with none saline irrigation water compared to saline irrigation water.   It was concluded that irrigating spinach with saline water of more than 2.0 dS/m drastically reduce plant growth but not the number of leaves under the conditions of the experiment.

scholarly journals Quantifying the Impacts of Compound Extremes on Agriculture and Irrigation Water Demand

2020 ◽  
Author(s):  
Iman Haqiqi ◽  
Danielle S. Grogan ◽  
Thomas W. Hertel ◽  
Wolfram Schlenker
Keyword(s):  
Heat Stress ◽  
Water Stress ◽  
Irrigation Water ◽  
Water Demand ◽  
Crop Production ◽  
Crop Yields ◽  
Fold Increase ◽  
The United States ◽  
Food Prices ◽  
Irrigation Water Demand

Abstract. Agricultural production and food prices are affected by hydroclimatic extremes. There has been a large literature measuring the impacts of individual extreme events (heat stress or water stress) on agricultural and human systems. Yet, we lack a comprehensive understanding of the significance and the magnitude of the impacts of compound extremes. Here, we combine a high-resolution weather product with fine-scale outputs of a hydrological model to construct functional indicators of compound hydroclimatic extremes for agriculture. Then, we measure the impacts of individual and compound extremes on crop yields focusing on the United States during the 1981–2015 period. Supported by statistical evidence, we confirm that wet heat is more damaging than dry heat for crops. We show that the average damage from heat stress has been up to four times more severe when combined with water stress; and the value of water experiences a four-fold increase on hot days. In a robust framework with only a few parameters of compound extremes, this paper also improves our understanding of the conditional marginal value (or damage) of water in crop production. This value is critically important for irrigation water demand and farmer decision-making – particularly in the context of supplemental irrigation and sub-surface drainage.

Estimating rice water requirements in the Lis Valley (Portugal) using remote sensing platforms: preliminary results for the 2020 cultivation season

2021 ◽  
Author(s):  
Romeu G. Jorge ◽  
Isabel P. de Lima ◽  
João L.M.P. de Lima
Keyword(s):  
Water Management ◽  
Remote Sensing ◽  
Irrigation Water ◽  
Crop Yields ◽  
Irrigation District ◽  
Water Requirements ◽  
Local Conditions ◽  
Preliminary Results ◽  
Sentinel 2A ◽  
Rice Water

&lt;p&gt;In irrigated agricultural areas, where the availability of water for irrigation does not rely on any water storage, water management requires special attention, in particular under large annual and inter-annual variability in the hydrological regime and the uncertainty of climate change. The inherent increased vulnerability of the agro-ecosystem, makes the monitoring of crop conditions and water requirements a valuable tool for improving water use efficiency and, therefore, crop yields.&lt;/p&gt;&lt;p&gt;This presentation focus on one such agricultural area, located in the Lis Valley (Centre of Portugal), which is a rather vulnerable area also facing drainage and salinity problems. The study aims at contributing to better characterizing the temporal and spatial distribution of rice water requirements during the growing season. Irrigation water sources are the Lis River and its tributaries, which discharges depend directly from precipitation. The most important problems of water distribution in the Lis Valley irrigation district are water shortage and poor water quality in the dry summer period, aggravated by limitations of the irrigation and drainage systems that date back to the end of the 1950&amp;#8217;s.&lt;/p&gt;&lt;p&gt;We report preliminary results on using remote sensing data to better understand rice cropping local conditions, obtained within project GO Lis (PDR2020-101-030913) and project MEDWATERICE (PRIMA/0006/2018). Rice irrigation is traditionally conducted applying continuous flooding, which requires much more irrigation water than non-ponded crops, and therefore needs special attention. In particular, data obtained from satellite Sentinel-2A land surface imagery are compared with data obtained using an unmanned aerial vehicle (UAV). Data for rice cultivated areas during the 2020 cultivation season, together with weather and crop parameters, are used to calculate biophysical indicators and indices of water stress in the vegetation. Actual crop evapotranspiration was appraised with remote sensing based estimates of the crop coefficient (Kc) and used to assess rice water requirements. Procedures and methodologies to estimate Kc were tested, namely those based on vegetation indices such as the Normalized Difference Vegetation Index (NDVI). Results are discussed bearing in mind the usefulness of the diverse tools, based on different resolution data (Sentinel-2A and UAV), for improving the understanding of the impacts of irrigation practices on crop yield and main challenges of rice production and water management in the Lis Valley irrigation district.&lt;/p&gt;

Irrigation management through a coupled energy-water balance and crop growth model driven by remote sensing data

2021 ◽  
Author(s):  
Marco Mancini ◽  
Chiara Corbari ◽  
Imen Ben Charfi ◽  
Ahmad Al Bitar ◽  
Drazen Skokovic ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Water Use ◽  
Irrigation Water ◽  
Crop Yields ◽  
Irrigation Management ◽  
Balance Model ◽  
Soil Parameters ◽  
Area Index ◽  
Landsat 7

&lt;p&gt;The conflicting use of water is becoming more and more evident, also in regions that are traditionally rich in water. With the world&amp;#8217;s population projected to increase to 8.5 billion by 2030, the simultaneous growth in income will imply a substantial increase in demand for both water and food. Climate change impacts will further stress the water availability enhancing also its conflictual use. The agricultural sector is the biggest and least efficient water user, accounts for around 24% of total water use in Europe, peaking at 80% in the southern regions.&lt;/p&gt;&lt;p&gt;This paper shows the implementation of a system for real-time operative irrigation water management at high spatial and temporal able to monitor the crop water needs reducing the irrigation losses and increasing the water use efficiency, according to different agronomic practices supporting different level of water users from irrigation consortia to single farmers. The system couples together satellite (land surface temperature LST and vegetation information) and ground data, with pixel wise hydrological crop soil water energy balance model. In particular, the SAFY (Simple Algorithm for Yield) crop model has been coupled with the pixel wise energy water balance FEST-EWB model, which assimilate satellite LST for its soil parameters calibration. The essence of this coupled modelling is that the SAFY provides the leaf area index (LAI) evolution in time used by the FEST-EWB for evapotranspiration computation while FEST-EWB model provides soil moisture (SM) to SAFY model for computing crop grow for assigned water content.&lt;/p&gt;&lt;p&gt;The FEST-EWB-SAFY has been firstly calibrated in specific fields of Chiese (maize crop) and Capitanata (tomatoes) where ground measurements of evapotranspiration, soil moisture and crop yields are available, as well as LAI from Sentinel2-Landsat 7 and 8 data. The FEST-EWB-SAFY model has then been validated also on several fields of the RICA farms database in the two Italian consortia, where the economic data are available plus the crop yield. Finally, the modelled maps of LAI have then been validated over the whole Consortium area (Chiese and Capitanata) against satellite data of LAI from Landsat 7 and 8, and Sentinel-2.&lt;/p&gt;&lt;p&gt;Optimized irrigation volumes are assessed based on a soil moisture thresholds criterion, allowing to reduce the passages over the field capacity threshold reducing the percolation flux with a saving of irrigation volume without affecting evapotranspiration and so that the crop production. The implemented strategy has shown a significative irrigation water saving, also in this area where a traditional careful use of water is assessed.&lt;/p&gt;&lt;p&gt;The activity is part of the European project RET-SIF (www.retsif.polimi.it).&lt;/p&gt;

scholarly journals Crop-specific seasonal estimates of irrigation-water demand in South Asia

2016 ◽  
Vol 20 (5) ◽  
pp. 1971-1982 ◽  
Author(s):  
Hester Biemans ◽  
Christian Siderius ◽  
Ashok Mishra ◽  
Bashir Ahmad
Keyword(s):  
South Asia ◽  
Irrigation Water ◽  
Water Demand ◽  
Crop Yields ◽  
Seasonal Pattern ◽  
State Level ◽  
Multiple Cropping ◽  
Planting Dates ◽  
Irrigation Water Demand ◽  
Regional Estimates

Abstract. Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight into these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation-water demand resulting from the typical practice of multiple cropping in South Asia was accounted for by introducing double cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest state-level statistics of India, Pakistan, Bangladesh and Nepal. The improvements in seasonal land use and cropping periods lead to lower estimates of irrigation-water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation-water demand differs sharply between seasons and regions; in Pakistan, winter (rabi) and monsoon summer (kharif) irrigation demands are almost equal, whereas in Bangladesh the rabi demand is  ∼  100 times higher. Moreover, the relative importance of irrigation supply versus rain decreases sharply from west to east. Given the size and importance of South Asia improved regional estimates of food production and its irrigation-water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple cropping and monsoon-dependent planting dates should not be ignored.

A comparison of ley and arable farming systems

1960 ◽  
Vol 54 (3) ◽  
pp. 310-317 ◽  
Author(s):  
A. H. Lewis ◽  
John Procter ◽  
A. E. M. Hood
Keyword(s):  
Detrimental Effect ◽  
Crop Yields ◽  
Residual Effect ◽  
Farming Systems ◽  
Nutrient Status ◽  
Fertilizer N ◽  
Wheat Grain ◽  
Arable Crops ◽  
Weed Growth ◽  
Arable Farming

1. Alternate husbandry systems containing 1-, 2- and 3-year grazed leys were compared with continuous arable cropping at Jealott's Hill during the period 1945–56. Kale and wheat were used as successive test crops to measure the fertility accruing from the following crop sequences: (a) 3-year ley; (b) wheat, 2-year ley; (c) wheat, barley, 1-year ley; (d) wheat, barley, barley. A study was also made of the effect on crop yields of compost, dung and N fertilizer dressings applied to kale.2. The yields of kale and wheat were improved considerably by 1-, 2- and 3-year leys. Increments were: 5·2 tons fresh kale per acre and 8·7 cwt. wheat grain per acre from 1-year ley, 9·0 tons kale and 13·5 cwt. wheat per acre from 2-year ley and 9·2 tons kale and 15·0 cwt. wheat per acre from 3-year ley. Two- and 3-year leys were markedly superior to 1-year ley in their effects on kale and wheat. The slight benefit apparent in wheat yields from 3-year ley compared with 2-year ley was not significant and so the 2- and 3-year leys may be considered equal in their effect on the succeeding arable crops. In the third arable crop, wheat, the 2-year ley was still effective to the extent of 3·9 cwt. grain per acre but the residual effect of the 1-year ley had largely disappeared. Yields under the all-arable system were considered to have been reduced by the poor physical and nutrient status of the soil, by increased incidence of ‘take-all’ in wheat and by more weed growth.3. The response of kale to dung averaged only 1·1 tons per acre over all four rotations but this was largely obtained in the ley systems and little after all-arable cropping. Compost was generally ineffective on kale with some signs of detrimental effect, especially in the arable system. Wheat following kale benefited equally from dung and compost applied in the previous year; the average response to organics was 1·6 cwt. grain per acre and this was unaffected by rotation. The residual value of dung on subsequent crops amounted to an average of 2·0 cwt. grain per acre per annum but compost had no significant effect.4. The response to an additional 0·4 cwt. fertilizer N per acre to kale was greatest after continuous arable cropping and virtually nil after 3-year ley. Wheat grain yields were improved by 1·0 cwt. per acre on average by the addition of the extra 0·4 cwt. fertilizer N per acre to kale in the previous year.5. It was concluded that when mixed farming is practised the aim should be to have the land under grass for at least as long as it is under arable, e.g. 3 years of ley with 3 years of arable.

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