Using a Crop Simulation Model to Understand the Impact of Risk Aversion on Optimal Irrigation Management

2017 ◽  
Vol 60 (6) ◽  
pp. 2111-2122 ◽  
Author(s):  
Rulianda P. Wibowo ◽  
Nathan P. Hendricks ◽  
Isaya Kisekka ◽  
Alemie Araya

Abstract. We studied optimal irrigation management by risk-averse farmers with different soil types under limited well capacity. Our modeling framework allowed us to assess the optimal adjustment along the intensive margins (i.e., changes in seasonal irrigation depth) and along the extensive margins (i.e., changes in irrigated area). Our empirical application uses AquaCrop to simulate corn yields with historical weather in southwest Kansas under a large number of potential irrigation strategies. We show that risk aversion significantly increases total water use, especially for low and medium well capacities. While farmers decreased irrigated area due to risk aversion, the increase in water use occurred because it was optimal to increase the seasonal irrigation depth to reduce production risk. The increase in seasonal irrigation depth arises mostly from reduced management allowable depletion (MAD) levels in the initial crop growth stages of corn. Counterintuitively, risk aversion had a smaller impact on water use for a soil with a smaller soil water holding capacity. This result arises because optimal irrigation under risk neutrality is larger for soils with a smaller water holding capacity. Our results highlight the importance of accounting for risk aversion when estimating the optimal irrigation management strategy and show that the impact of risk aversion differs significantly by well capacity and soil type. Keywords: AquaCrop, Irrigation, Risk, Well capacity.

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2208
Author(s):  
Mohd Shahkhirat Norizan ◽  
Aimrun Wayayok ◽  
Ahmad Fikri Abdullah ◽  
Muhammad Razif Mahadi ◽  
Yahya Abd Abd Karim

Malaysia receives a lot of water from its two main monsoon periods. Generally, there is a lot of precipitation throughout the year, with drought periods lasting less than three months. To date, irrigation has been treated homogenously, even though soil properties can vary spatially over a field, requiring site-specific applications. The aim of this study was to establish an irrigation management zone (IMZ) covering 23.4 ha, which was previously determined under the same soil series. Soil sampling was done according to a grid system over an area of 100 m × 100 m. Three soil depth ranges were examined for every sampling point, namely 0–30, 30–60, and 60–90 cm from the soil surface. Samples were taken to a laboratory for physical analysis and determination of the available water-holding capacity (AWHC). Delineation of AWHC values was achieved using GIS software and the Kriging method. Estimated irrigation depth (EID) data for the plantation were collected for the years 2016 and 2017. Afterward, EID and total net irrigation (TNI) data were simulated in the FAO Cropwat model and compared. The results showed that clay, sand, and organic matter (OM) distributions varied with soil depth; however, no strong correlation was found between these variable with AWHC. The IMZ was classified into three areas named zones A, B, and C, ranging from 79 to 167 mm. The crop water requirement (CWR) was 667 mm in 2016 but only 260 mm in 2017. Based on the AWHC values, the EID for 2016 was found to be below the TNI requirement range of about 106 to 110 mm. In contrast, the EID range was approximately 34 to 62 mm and above TNI requirements for 2017. This study indicates that water inputs for irrigation can be optimized with knowledge of the water-holding capacity of a specific soil. Subsequently, this can be related to crop yield and the impact on sustainable agriculture.


Irriga ◽  
2015 ◽  
Vol 20 (3) ◽  
pp. 528-543 ◽  
Author(s):  
Marcelo Rossi Vicente ◽  
Everardo Chartuni Mantovani ◽  
ANDRÉ LUÍS TEIXEIRA FERNANDES ◽  
FÁBIO TEIXEIRA DELAZARI ◽  
EDMILSON MARQUES FIGUEREDO

EFEITO DE DIFERENTES LÂMINAS DE IRRIGAÇÃO NAS VARIÁVEIS DE DESENVOLVIMENTO E PRODUÇÃO DO CAFEEIRO IRRIGADO POR PIVÔ CENTRAL  MARCELO ROSSI VICENTE1; EVERARDO CHARTUNI MANTOVANI2; ANDRÉ LUÍS TEIXEIRA FERNANDES3; FÁBIO TEIXEIRA DELAZARI4 E EDMILSON MARQUES FIGUEREDO5 1 Instituto Federal do Norte de Minas Gerais, Salinas, MG, [email protected] Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Viçosa, MG, [email protected] Universidade de Uberaba, Uberaba, MG, Fábio Teixeira Delazari, [email protected] Departamento de Fitotecnia, Universidade Federal de Viçosa, Viçosa, MG, [email protected] Bahia Farm Show, Luís Eduardo Magalhães, BA, [email protected]  1      RESUMO O presente trabalho foi conduzido com objetivo de avaliar o efeito de diferentes lâminas de irrigação nas variáveis de produção, estádios maturação de frutos e eficiência no uso da água pela cultura do cafeeiro irrigado por pivô central equipado com emissores LEPA, na região Oeste da Bahia. Realizou-se o trabalho na fazenda Café do Rio Branco, localizada em Barreiras - BA em cafeeiros adultos da variedade Catuaí IAC 144. O experimento obedeceu ao delineamento de blocos casualizados, composto de cinco tratamentos correspondentes à 70, 85, 100, 125 e 150% da lâmina de irrigação determinada pelo software Irriplus. As produtividades, os estádios de maturação dos frutos e eficiência no uso da água do cafeeiro foram submetidos à análise de variância e regressão, em que os modelos foram escolhidos baseados na significância dos coeficientes de regressão utilizando-se o teste t de 1 a 10% de probabilidade. Diante dos resultados obtidos, pode-se concluir que, a produtividade da cultura do café foi expressivamente dependente da lâmina de água aplicada, sendo que a maior produtividade (60 sc ha-1) foi alcançada com a lâmina de irrigação acumulada de 661 mm ano-1, correspondente à 96% da lâmina de irrigação determinada pelo software Irriplus. A lâmina que proporcionou a máxima porcentagem de frutos cereja (44,1%) foi de 723 mm ano-1 (105%). A lâmina que proporcionou a maior eficiência no uso da água foi de 480 mm ano-1 (70%). Palavras-Chave: Coffea arabica, manejo da irrigação, emissor LEPA, uso eficiente da água.  VICENTE, M. R.; MANTOVANI, E. M.; FERNANDES, A. L. T.; DELAZARI, F. T.; FIGUEREDO, E. M.EFFECTS OF DIFFERENT LEVELS OF IRRIGATION DEPTHS   ON GROWTH AND PRODUCTION VARIABLES OF COFFEE UNDER CENTER PIVOT  IRRIGATION     2        ABSTRACT This study aimed to evaluate the effect of different irrigation depths on yield, ripening stages and water use efficiency by the   coffee crop irrigated by center pivot with LEPA emitters in western Bahia. The experiment was carried out at the Café Rio Branco farm, in Barreiras city, Bahia state, using  adult coffee trees of cv. Catuaí IAC 144. A completely randomized block design was used with five treatments consisting of 70, 85, 100, 125 and 150 % of ETc, determined by the Irriplus software.  Data of yield, fruit ripening stage and water use efficiency were evaluated   using analyses of variance  and regression. Models were chosen based on level of significance of   regression coefficients using the Student´s t-test, 1 to  10% probability.  Based on the results,  coffee crop yield was highly dependent on  the water depth applied. The highest yield (3.6 ton/ha) was achieved  using accumulated irrigation depth of 661 mm year -1 (96 % of Etc).  Water depths of   723 mm year-1 (105 %) and 480 mm year-1 (70% ETc)  provided the highest percentage of cherry fruit (44.1%) and the highest water use efficiency, respectively. Keywords: Coffea arábica, irrigation management, LEPA emitter, water use efficiency.


1974 ◽  
Vol 5 (3) ◽  
pp. 166-172 ◽  
Author(s):  
BENGT ROGNERUD ◽  
KNUT VÅRUM

This article describes an investigation of irrigation and water use in an area with wooden shelter belts. Soil moisture was measured using a neutron moisture probe and tensiometers. The soil is deep and the water holding capacity is very high. Values of actual evapotranspiration on irrigated and non-irrigated plots are presented.


Scientifica ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Belkacem EL Amrani ◽  
Mohammed Bendriss Amraoui

The biomechanical root flexibility in response to hydromechanical soil heterogeneity is the most determining factor of the root architecture which plays a paramount role in mycorrhizal infection and allows the seedlings to adapt to the environmental constraint. We examined the impact of five different hydromechanical medium properties (hydroponics, vermiculite, vermiculite-gravel, sawdust, and sand) on the morphology, physiology, and anatomy of Cedrus atlantica seedlings at a controlled growth chamber. The growth of the seedling is strongly stimulated by the hydroponic medium through the stimulation of the aerial part dry weight and the main root length. However, the sand medium increases the main root dry weight by the radial expanse stimulation at the level of the epidermis, vascular cylinder, and cortex and compensates the less root architecture by the stimulation of the xylem and phloem areas. In contrast to sand and hydroponic media, the sawdust medium stimulates the phloem/xylem ratio, the root architecture, and the short roots. The Pearson bilateral correlation shows that the aerial part dry weight is positively correlated with the permeability, porosity, and water-holding capacity and negatively with the bulk density and density at saturation, whereas the short root production is negatively correlated with the permeability and water-holding capacity. Hence, the hydromechanical characteristics of the soils must be taken into account in the reforestation and mycorrhization attempts.


2012 ◽  
Vol 32 (2) ◽  
pp. 315-325 ◽  
Author(s):  
Francimar da S. Albuquerque ◽  
Ênio F. de F. e Silva ◽  
Marcus F. F. N. Nunes ◽  
Amanda E. R. de Souza

The use of productivity information and efficiency of water use is important for the economic analysis of production and irrigation management, and also helps the economy of water use, which is essential to plant life. The objective of this study was to evaluate the biomass allocation, the water use efficiency and water content in fruits of sweet pepper cropped under the influence of irrigation blades and potassium doses. The statistic design was a completely randomized factorial scheme (5 x 2) and four replications, with five irrigation blades (80; 90; 100; 110 and 120% of crop evapotranspiration) and two levels of potassium (80 and 120 kg K2O ha-1 ), applied according to phenological phase, through a system of drip irrigation with self-compensated drippers, installed in a battery of 40 drainage lysimeters cultivated with sweet pepper (Maximos F1), at Federal Rural University of Pernambuco (UFRPE), Recife, state of Pernambuco, Brazil. The dry biomass production of sweet pepper was influenced by fertigation regimes; when it was set the lowest dose, estimates of the efficiency of water use and moisture in the fruit occurred with the use of irrigation depth of 97 and 95% of ETc, respectively.


2020 ◽  
Author(s):  
Naeema Al Nofeli ◽  
Fred Worrall

<p><span>The date palm tree has been mainly used as a source of food in the MENA (Middle East North Africa) region. Specifically, in the United Arab Emirates produces over 44 million date palm trees yearly, each tree generates approximately 20 Kilograms of palm frond waste per year and this waste is currently sent to landfills. In this study, we proposed that in the arid soil conditions found in the UAE, this date palm waste could be converted to biochar and used to improve the water holding capacity of UAE soils. Therefore, the aim of this study was to test whether amendments of date palm frond (DPF) and its biochar could improve the water holding capacity of soils. A mesocosm design and a plant growth experiment were used to assess the treatments at summer temperature conditions. For the mesocosm, there were 6 different biochar and DPF treatments (1%, 3%, 6%, 12%, 15% and 18% biochar or DPF in soil) along with the controls (sharp sand, DPF biochar and DPF). The experiment was divided into 3 cycles (wet, dry, and dry with a water bowl (waw)). The impact of the experimental treatments was assessed using ANOVA. Both Biochar and DPF had no significant effect during the first two cycles (wet and dry) but during the third cycle, the DPF appeared to have better water holding capacity than Biochar. A plant growth experiment was conducted with 6 different treatment (controls - sand, DPF and Biochar; and Biochar at 1%, 6%,15% and 18%). Cat grass was used for measuring its temperature, height, moisture and pH. Water was irrigated during the first 3 weeks then the soil treatments left to dry. The results of the greatest growth for 1% Biochar. Further investigations are being processed using thermal gravimetric analysis (TGA), Carbon, Nitrogen, Hydrogen & Oxygen (CHNO), </span><span>Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM) & Computerized tomography (CT) scan.</span><span> This is to assess water binding capacity and physiochemical properties of the Biochar, DPF and soil.  </span></p>


2006 ◽  
Vol 46 (4) ◽  
pp. 579 ◽  
Author(s):  
S. Sivapalan

The productivity of sandy soils is mostly limited by their low water-holding capacity and excessive deep percolation losses, which reduce the efficiency of water and fertiliser use by plants. The effect of a crosslinked-type polyacrylamide, ALCOSORB 400, on water-holding capacity of a sandy soil, siliceous sands, was studied under the laboratory and glasshouse conditions. Water-holding capacity of the soil exposed to 0.01 MPa increased by 23 and 95% by adding 0.03 and 0.07% of polyacrylamide to the soil, respectively. This indicated that the soil treated with polyacrylamide was able to store more water than untreated soil, thereby reducing the potential losses due to deep percolation in sandy soils. However, the polyacrylamide in the treated soil did not significantly increase the quantity of water released from the soil by increasing the pressure from 0.01 to 1.5 MPa. The results from the first glasshouse experiment demonstrated that the excess amount of water stored in the soil by polyacrylamide was available to plants and resulted in higher water use and grain production. Consequently, there was a 12 and 18 fold increase in water use efficiency of soybean plants grown in soils treated with 0.03 and 0.07% polyacrylamide, respectively. The results from the second glasshouse experiment demonstrated that increasing amounts of polyacrylamides in a sandy soil can extend the irrigation interval without any adverse effect on the grain yield of soybeans.


2019 ◽  
Vol 76 ◽  
pp. 147-157
Author(s):  
Alpaslan Kusvuran ◽  
Sebnem Kusvuran

Drought is a significant environmental stress that limits plant growth and yield. In this study, an investigation of guar, grown under different drought level conditions [(S0: 100% of field capacity), S1 (depletion of 75% the available water holding capacity), S2 (depletion of 50% the available water holding capacity), S3 (depletion of 25% the available water holding capacity), S4 (no applied irrigation water)] with regards to the impact of Chlorella vulgaris based microbial fertilizer on physiological, morphological, and enzymatic activity was performed. Microbial fertilizer applications significantly increased shoot length, fresh and dry weight of the shoot and root, and leaf number and area of guar plants compared to the only drought stress treatments. In addition, following the above-mentioned procedures, there were significant increases in the relative water content, total phenolic and flavonoid contents, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutation reductase (GR) activity. However, the malondialdehyde (MDA) content were significantly decreased. Hence, the results support the administration of a foliar application to the microbial fertilizer containing microalgae in order to increase the guar plant’s defense system, enabling it to tolerate the negative effects resulting from drought stress.


2021 ◽  
Author(s):  
Ceres Duarte Guedes Cabral de Almeida ◽  
Leandro Candido Gordin ◽  
Alexsandro Cláudio dos Santos Almeida ◽  
José Amilton Santos Júnior ◽  
Brivaldo Gomes de Almeida ◽  
...  

<p>Several methodologies and techniques are available for irrigation management in protected environments. Despite the cultivation of vegetables in the greenhouse is largely present in the northeastern region of Brazil, not many research has been aimed at supporting growers for accurate irrigation management.</p><p>The objective of this study is to evaluate yield and irrigation water use efficiency of Capsicum crop cultivated in a greenhouse under different methods to define the daily irrigation depth, based on the soil water status and the atmospheric evaporative demand. Moreover, two different strategies to apply the estimated irrigation depths (single or double daily application) were also examined.</p><p>The experiment was carried out in a greenhouse in the Federal Rural University of Pernambuco (UFRPE), northeastern of Brazil (8° 01’ 07” S and 34° 56’ 53” W, altitude 6.50 m). Based on a completely randomized design, the experimental units were distributed according to a 4 x 2 factorial scheme with eight replications, with a total of 64 experimental units. Four methods to estimate daily irrigation water requirement were evaluated: two based on soil sensors (soil water content sensors EC-5, SWS, and tensiometers, TS), whereas the other two were based on the atmospheric evaporative demand (weighing lysimeter, WL, and Piché evaporimeter, PE). Moreover, the daily irrigation depths were applied with a single watering (at 8:00 am) or split into two applications (the half at 8:00 am and the half at 4:30 pm). The commercial yield of the examined crop was calculated through the relationship between the weight of fresh fruit and the area occupied by the plant.</p><p>The statistical analysis showed that the water use efficiency, the total water volume applied and the commercial yield of capsicum were significantly influenced by the method used to estimate crop water requirement, as well as the irrigation strategies. The total irrigation depth applied during the entire crop cycle resulted in equal to 509 mm, 678 mm, 716 mm, and 790 mm for treatments with WL, PE, SWS, and TS, respectively. The seasonal applied irrigation depths corresponded to an average daily crop water requirement ranging, according to the treatments, from 5.4 to 8.3 mm day<sup>-1</sup>; these values are consistent for the examined crop cultivated under protected conditions. The highest yields of commercial fruits were obtained in the treatments in which the highest irrigation depth (SWS and TS) was applied. On the other hand, the highest values of water use efficiency were obtained in those treatments in which the irrigation depth was defined based on SWS and WL. Splitting the estimated daily irrigation depth in two applications promoted greater commercial productivity and water use efficiency (10.73 t ha<sup>-1</sup> and 1.60 kg m<sup>-3</sup>) compared to a single application (8.14 t ha<sup>-1</sup> and 1.22 kg m<sup>-3</sup>), with an increase of both variables of about 31%. These results evidenced that splitting the daily irrigation depth is a promising strategy to increase water use efficiency for vegetable crops in protected environments.</p>


2021 ◽  
Author(s):  
Naeema Al Nofeli ◽  
Fred Worrall

<p>Many studies have indicated that biochar could retain water for an extended period of time. Very little has been demonstrated the behaviour of biochar in arid environments where water retention is vital. The United Arab Emirates is one of the warmest countries in the World where farmers enjoy harvesting more crops during winter, however, during summer date palm trees is one of the main sources of food.  About 44 million date palm trees produce approximately 20 Kilograms of palm frond waste per year per tree (which is around 0.88 million tons of date palm biomass annually). This waste is currently sent to landfills. In this study, we proposed that in the arid soil conditions found in the UAE, this date palm waste could be converted to biochar and used to improve the water holding capacity of UAE soils. Therefore, this study aimed to compare the water holding capacity of amendments of date palm frond (DPF) and its biochar in UAE soils in different local weather conditions (winter and summer). A mesocosm experiment was used to assess the treatments at summer and winter temperature conditions. For the mesocosm, there were 6 different biochar and DPF treatments (1%, 3%, 6%, 12%, 15% and 18% biochar or DPF in soil) along with the controls (sharp sand, DPF biochar and DPF). The experiment was divided into 3 cycles with varying modified humidity. The impact of the experimental treatments was assessed using ANOVA. Both biochar and DPF had no significant effect during the first two cycles (wet and dry) but during the third cycle, the DPF had a 1% better water holding capacity than biochar. Given the mass loss of 5.7% during the production of biochar from DPF. It would seem that the best option is simply use collected date palm fronds. Therefore, further investigations are being processed to assess water binding capacity and physiochemical properties of the biochar, DPF and soil. </p><p> </p><p> </p><p> </p><p> </p>


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