Trade-off between blue and grey water footprint of crop production at different nitrogen application rates under various field management practices

The water footprint (WF) is a spatially explicit character of water use in terms of consumption or pollution for producing a product, commodity or service. The WF of a crop may be defined as the amount of water required for producing the crop over the complete growing season. The present study was carried out to assess the WF of agriculture in Banjar river watershed (BRW) over the period 2000 - 2013. The WF of crops were evaluated and their further multiplication with production (ton/yr) in the watershed yielded the water footprint of crop production (WFCP) in Banjar river watershed whose further summation gave WF of agriculture in BRW. The findings depicted that the water footprint of rice was maximum (7848 m3/ton) followed by gram (5782 m3/ton) and wheat (5417 m3/ton). The crop with least WF was maize (2886 m3/ton). These values of WF are much higher than the national average WF for different crops grown in India. Lower crop yields due to improper irrigation practices, low fertilizer application rates and improper on farm water management practices are the primary reasons of such high values of WF of crops in BRW. The water footprint of agriculture in BRW was 690.37 million m3/yr with 59.74 % WFgreen, 39.69 % WFblue and 0.56 % WF grey. Rice was having maximum share in water footprint of agriculture in BRW with 87.38 % of total water footprint followed by gram (4.97 %), wheat (4.33 %) and maize (1.31%).

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The green, blue and grey water footprint of crops and derived crop products

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-8-763-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 763-809 ◽

Cited By ~ 47

Author(s):

M. M. Mekonnen ◽

A. Y. Hoekstra

Keyword(s):

Water Balance ◽

River Basin ◽

Crop Production ◽

Water Footprint ◽

Grid Cell ◽

Blue Water ◽

Total Water ◽

Grey Water ◽

Global Average ◽

Average Water

Abstract. This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment is global and improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc min grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the water footprint network. Considering the water footprints of primary crops, we see that global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton−1), vegetables (300 m3 ton−1), roots and tubers (400 m3 ton−1), fruits (1000 m3 ton−1), cereals} (1600 m3 ton−1), oil crops (2400 m3 ton−1) to pulses (4000 m3 ton−1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ−1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ−1, while this is 121 m3 GJ−1 for maize. The global water footprint related to crop production in the period 1996–2005 was 7404 billion cubic meters per year (78% green, 12% blue, 10% grey). A large total water footprint was calculated for wheat (1087 Gm3 yr−1), rice (992 Gm3 yr−1) and maize (770 Gm3 yr−1). Wheat and rice have the largest blue water footprints, together accounting for 45% of the global blue water footprint. At country level, the total water footprint was largest for India (1047 Gm3 yr−1), China (967 Gm3 yr−1) and the USA (826 Gm3 yr−1). A relatively large total blue water footprint as a result of crop production is observed in the Indus River Basin (117 Gm3 yr−1) and the Ganges River Basin (108 Gm3 yr−1). The two basins together account for 25% of the blue water footprint related to global crop production. Globally, rain-fed agriculture has a water footprint of 5173 Gm3 yr−1 (91% green, 9% grey); irrigated agriculture has a water footprint of 2230 Gm3 yr−1 (48% green, 40% blue, 12% grey).

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Quantifying Nitrogen Status of Rice Using Low Altitude UAV-Mounted System and Object-Oriented Segmentation Methodology

Volume 3: ASME/IEEE 2009 International Conference on Mechatronic and Embedded Systems and Applications; 20th Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2009-87107 ◽

2009 ◽

Cited By ~ 4

Author(s):

Jinxia Zhu ◽

Ke Wang ◽

Jinsong Deng ◽

Tom Harmon

Keyword(s):

Crop Production ◽

Nitrogen Deficiency ◽

Object Oriented ◽

Spatial And Temporal Variation ◽

Nitrogen Application ◽

Color Parameter ◽

Nitrogen Status ◽

Predictive Tool ◽

Nutrient Runoff ◽

Application Rates

Nitrogen deficiency can seriously reduce yield, while over-fertilization can result problems such as excess nutrient runoff and groundwater pollution. Hence, efficient methods for assessing crop nitrogen status are needed to enable more optimal fertilizer management. The ability to quantify the different nitrogen application rates by crops using digital images taken from an unmanned aerial vehicle (UAV) was investigated in comparison with ground-based hyperspectral reflectance and chlorophyll content data from 140 plots on a managed field. This research utilized new UAV system, comprised of remote-controlled helicopter (Hercules II) and digital camera (EOS 30D), was used to characterize spatial and temporal variation in crop production. Digital information was extracted based on an object-oriented segmentation method, and the color parameter was reduced and represented using principal component analysis (PCA). An estimating model was established after analyzing the relationship between the optimal color parameter and ground-based measurements. Model testing demonstrated that unknown samples could be associated with the controlled nitrogen application rates (0, 60, 90, and 120 kg N·hm−2): 91.6% %; N1 (60 kg N·hm−2): 70.83%; N2 (90 kg N·hm−2): 86.7%; N3 (120 kg N·hm−2): 95%. Overall, this result proved to provide a cost-effective and accurate way and the UAV was an exploratory and predictive tool when applied to quantify different status of nitrogen. In addition, it indicated that the application of digital image from UAV to the problem of estimating different nitrogen rates is promising.

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Carbon footprint of crop production in China: an analysis of National Statistics data

The Journal of Agricultural Science ◽

10.1017/s0021859614000665 ◽

2014 ◽

Vol 153 (3) ◽

pp. 422-431 ◽

Cited By ~ 48

Author(s):

K. CHENG ◽

M. YAN ◽

D. NAYAK ◽

G. X. PAN ◽

P. SMITH ◽

...

Keyword(s):

Carbon Footprint ◽

Crop Production ◽

Management Practices ◽

Fertilizer Application ◽

N Fertilization ◽

Paddy Rice ◽

N Fertilizer ◽

Carbon Equivalent ◽

Ghg Mitigation ◽

Application Rates

SUMMARYAssessing carbon footprint (CF) of crop production in a whole crop life-cycle could provide insights into the contribution of crop production to climate change and help to identify possible greenhouse gas (GHG) mitigation options. In the current study, data for the major crops of China were collected from the national statistical archive on cultivation area, yield, application rates of fertilizer, pesticide, diesel, plastic film, irrigated water, etc. The CF of direct and indirect carbon emissions associated with or caused by these agricultural inputs was quantified with published emission factors. In general, paddy rice, wheat, maize and soybean of China had mean CFs of 2472, 794, 781 and 222 kg carbon equivalent (CE)/ha, and 0·37, 0·14, 0·12 and 0·10 kg CE/kg product, respectively. For dry crops (i.e. those grown without flooding the fields: wheat, maize and soybean), 0·78 of the total CFs was contributed by nitrogen (N) fertilizer use, including both direct soil nitrous oxide (N2O) emission and indirect emissions from N fertilizer manufacture. Meanwhile, direct methane (CH4) emissions contributed 0·69 on average to the total CFs of flooded paddy rice. Moreover, the difference in N fertilizer application rates explained 0·86–0·93 of the provincial variations of dry crop CFs while that in CH4 emissions could explain 0·85 of the provincial variation of paddy rice CFs. When a 30% reduction in N fertilization was considered, a potential reduction in GHGs of 60 megatonne (Mt) carbon dioxide equivalent from production of these crops was projected. The current work highlights opportunities to gain GHG emission reduction in production of crops associated with good management practices in China.

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Agricultural Water Management Model Based on Grey Water Footprints under Uncertainty and its Application

Sustainability ◽

10.3390/su11205567 ◽

2019 ◽

Vol 11 (20) ◽

pp. 5567 ◽

Cited By ~ 3

Author(s):

Ge Song ◽

Chao Dai ◽

Qian Tan ◽

Shan Zhang

Keyword(s):

Water Use ◽

Crop Production ◽

Water Footprint ◽

Programming Model ◽

Economic Benefits ◽

Irrigation District ◽

Agricultural Water ◽

Grey Water ◽

Availability Constraints ◽

Negative Impacts

The grey water footprint theory was introduced into a fractional programming model to alleviate non-point source pollution and increase water-use efficiency through the adjustment of crop planting structure. The interval programming method was also incorporated within the developed framework to handle parametric uncertainties. The objective function of the model was the ratio of economic benefits to grey water footprints from crop production, and the constraints contained water availability constraints, food security constraints, planting area constraints, grey water footprint constraints and non-negative constraints. The model was applied to the Hetao Irrigation District of China. It was found that, based on the data in the year of 2016, the optimal planting plans generated from the developed model would reduce 34,400 m3 of grey water footprints for every 100 million Yuan gained from crops. Under the optimal planting structure, the total grey water footprints would be reduced by 21.9 million m3, the total economic benefits from crops would be increased by 1.138 billion Yuan, and the irrigation water would be saved by 44 million m3. The optimal results could provide decision-makers with agricultural water use plans with reduced negative impacts on the environment and enhanced economic benefits from crops.

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Optimizing nitrogen fertilizer use for more grain and less pollution

10.21203/rs.3.rs-361734/v1 ◽

2021 ◽

Author(s):

Keyu Ren ◽

Minggang Xu ◽

Rong Li ◽

Lei Zheng ◽

Shaogui Liu ◽

...

Keyword(s):

Crop Production ◽

Management Practices ◽

Application Rate ◽

N Fertilizer ◽

N Application ◽

Fertilizer Use ◽

Application Rates ◽

Operational Practices ◽

N Management ◽

N Fertilizer Use

Abstract Optimal nitrogen (N) management is critical for efficient crop production and agricultural pollution control. However, it is difficult to implement advanced management practices on smallholder farms due to a lack of knowledge and technology. Here, using 35,502 on-farm fertilization experiments, we demonstrated that smallholders in China could produce more grain with less N fertilizer use through optimizing N application rate. The yields of wheat, maize and rice were shown to increase between 10% and 19% while N application rates were reduced by 15–19%. These changes resulted in an increase in N use efficiency (NUE) by 32–46% and a reduction in N surplus by 40% without actually changing farmers’ operational practices. By reducing N application rates in line with official recommendations would not only save fertilizer cost while increasing crop yield, but at the same time reduce environmental N pollution in China. However, making progress towards further optimizing N fertilizer use to produce more grain with less pollution would require managements to improve farmers’ practices which was estimated to cost about 11.8 billion US dollars to implement.

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Grey water footprint reduction in irrigated crop production: effect of nitrogen application rate, nitrogen form, tillage practice and irrigation strategy

Hydrology and Earth System Sciences ◽

10.5194/hess-22-3245-2018 ◽

2018 ◽

Vol 22 (6) ◽

pp. 3245-3259 ◽

Cited By ~ 18

Author(s):

Abebe D. Chukalla ◽

Maarten S. Krol ◽

Arjen Y. Hoekstra

Keyword(s):

Water Pollution ◽

Crop Yield ◽

Deficit Irrigation ◽

Crop Production ◽

Water Footprint ◽

Application Rate ◽

Inorganic N ◽

N Application ◽

Grey Water ◽

N Application Rate

Abstract. Grey water footprint (WF) reduction is essential given the increasing water pollution associated with food production and the limited assimilation capacity of fresh water. Fertilizer application can contribute significantly to the grey WF as a result of nutrient leaching to groundwater and runoff to streams. The objective of this study is to explore the effect of the nitrogen application rate (from 25 to 300 kg N ha−1), nitrogen form (inorganic N or manure N), tillage practice (conventional or no-tillage) and irrigation strategy (full or deficit irrigation) on the nitrogen load to groundwater and surface water, crop yield and the N-related grey water footprint of crop production by a systematic model-based assessment. As a case study, we consider irrigated maize grown in Spain on loam soil in a semi-arid environment, whereby we simulate the 20-year period 1993–2012. The water and nitrogen balances of the soil and plant growth at the field scale were simulated with the Agricultural Policy Environmental eXtender (APEX) model. As a reference management package, we assume the use of inorganic N (nitrate), conventional tillage and full irrigation. For this reference, the grey WF at a usual N application rate of 300 kg N ha−1 (with crop yield of 11.1 t ha−1) is 1100 m3 t−1, which can be reduced by 91 % towards 95 m3 t−1 when the N application rate is reduced to 50 kg N ha−1 (with a yield of 3.7 t ha−1). The grey WF can be further reduced to 75 m3 t−1 by shifting the management package to manure N and deficit irrigation (with crop yield of 3.5 t ha−1). Although water pollution can thus be reduced dramatically, this comes together with a great yield reduction, and a much lower water productivity (larger green plus blue WF) as well. The overall (green, blue and grey) WF per tonne is found to be minimal at an N application rate of 150 kg N ha−1, with manure, no-tillage and deficit irrigation (with crop yield of 9.3 t ha−1). The paper shows that there is a trade-off between grey WF and crop yield, as well as a trade-off between reducing water pollution (grey WF) and water consumption (green and blue WF). Applying manure instead of inorganic N and deficit instead of full irrigation are measures that reduce both water pollution and water consumption with a 16 % loss in yield.

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Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

Hydrology and Earth System Sciences ◽

10.5194/hess-19-4877-2015 ◽

2015 ◽

Vol 19 (12) ◽

pp. 4877-4891 ◽

Cited By ~ 87

Author(s):

A. D. Chukalla ◽

M. S. Krol ◽

A. Y. Hoekstra

Keyword(s):

Crop Production ◽

Management Practices ◽

Water Footprint ◽

Sandy Loam ◽

Management Practice ◽

Furrow Irrigation ◽

Irrigated Agriculture ◽

Silty Clay ◽

Reference Case ◽

Aquacrop Model

Abstract. Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8–10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17–18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

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Long-Term Response of Groundwater Nitrate Concentrations to Management Regulations in Nebraska's Central Platte Valley

The Scientific World JOURNAL ◽

10.1100/tsw.2010.25 ◽

2010 ◽

Vol 10 ◽

pp. 286-297 ◽

Cited By ~ 25

Author(s):

Mary E. Exner ◽

Hugo Perea-Estrada ◽

Roy F. Spalding

Keyword(s):

Crop Production ◽

Management Practices ◽

Sprinkler Irrigation ◽

Fertilizer Application ◽

Application Rates ◽

Nitrate Concentrations ◽

Management Area ◽

Platte River Valley ◽

N Management ◽

The Impact

The impact of 16 years (1988–2003) of management practices on high groundwater nitrate concentrations in Nebraska's central Platte River valley was assessed in a 58,812-ha (145,215-ac) groundwater quality management area intensively cropped to irrigated corn (Zea maysL.). Crop production and groundwater nitrate data were obtained from ~23,800 producer reports. The terrace, comprising ~56% of the study area, is much more intensively cropped to irrigated corn than the bottomland. From 1987 to 2003, average groundwater nitrate concentrations in the primary aquifer beneath the bottomland remained static at ~8 mg N/l. During the same period, average groundwater nitrate concentrations in the primary aquifer beneath the terrace decreased from 26.4 to 22.0 mg N/l at a slow, but significant (p< 0.0001), rate of 0.26 mg N/l/year. Approximately 20% of the decrease in nitrate concentrations can be attributed to increases in the amount of N removed from fields as a consequence of small annual increases in yield. During the study, producers converted ~15% of the ~28,300 furrow-irrigated terrace hectares (~69,800 ac) to sprinkler irrigation. The conversion is associated with about an additional 50% of the decline in the nitrate concentration, and demonstrates the importance of both improved water and N management. Average N fertilizer application rates on the terrace were essentially unchanged during the study. The data indicate that groundwater nitrate concentrations have responded to improved management practices instituted by the Central Platte Natural Resources District.

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Grey water footprint reduction in irrigated crop production: effect of nitrogen application rate, nitrogen form, tillage practice and irrigation strategy

10.5194/hess-2017-224 ◽

2017 ◽

Cited By ~ 2

Author(s):

Abebe D. Chukalla ◽

Maarten S. Krol ◽

Arjen Y. Hoekstra

Keyword(s):

Water Pollution ◽

Crop Yield ◽

Deficit Irrigation ◽

Crop Production ◽

Water Footprint ◽

Application Rate ◽

Inorganic N ◽

N Application ◽

Grey Water ◽

N Application Rate

Abstract. Grey water footprint (WF) reduction is essential given the increasing water pollution associated with food production and the limited assimilation capacity of fresh water. Fertilizer application can contribute significantly to the grey WF as a result of nutrient leaching to groundwater and runoff to streams. The objective of this study is to explore the effect of the nitrogen application rate (from 25 to 300 kg N ha−1), nitrogen form (inorganic-N or manure-N), tillage practice (conventional or no-tillage) and irrigation strategy (full or deficit irrigation) on the nitrogen load to groundwater and surface water, crop yield and the grey water footprint of crop production by a systematic model-based assessment. As a case study, we consider irrigated maize grown in Spain on loam soil in a semi-arid environment, whereby we simulate the twenty-years period 1993–2012. The water and nitrogen balances of the soil and plant growth at field scale were simulated with the APEX model. As a reference management package, we assume the use of inorganic-N (nitrate), conventional tillage and full irrigation. For this reference, the grey WF at a usual N application rate of 300 kg N ha−1 (with crop yield of 11.1 t ha−1) is 1100 m3 t−1, which can be reduced by 91 % towards 95 m3 t−1 when the N application rate is reduced to 50 kg N ha−1 (with a yield of 3.7 t ha−1). The grey WF can be further reduced to 75 m3 t−1 by shifting the management package to manure-N and deficit irrigation (with crop yield of 3.5 t ha−1). Although water pollution can thus be reduced dramatically, this comes together with a great yield reduction, and a much lower water productivity (larger green plus blue WF) as well. The overall (green, blue plus grey) WF per tonne is found to be minimal at an N application rate of 150 kg N ha−1, with manure, no-tillage and deficit irrigation (with crop yield of 9.3 t ha−1). The paper shows that there is a trade-off between grey WF and crop yield, as well as a trade-off between reducing water pollution (grey WF) and water consumption (green and blue WF). Applying manure instead of inorganic-N and deficit instead of full irrigation are measures that reduce both water pollution and water consumption with a 16 % loss in yield.

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