scholarly journals Nutrient Management Programs, Nitrogen Fertilizer Practices, and Groundwater Quality in Nebraska’s Central Platte Valley (U.S.), 1989–1998

2001 ◽  
Vol 1 ◽  
pp. 750-757 ◽  
Author(s):  
Stan Daberkow ◽  
Harold Taylor ◽  
Noel Gollehon ◽  
Milt Moravek
Keyword(s):  
Irrigation Water ◽  
Fertilizer Application ◽  
Management Program ◽  
N Fertilizer ◽  
N Availability ◽  
Modest Improvement ◽  
Total N ◽  
Drinking Water Standard ◽  
Irrigation Water Use ◽  
Farmer Behavior

Given the societal concern about groundwater pollution from agricultural sources, public programs have been proposed or implemented to change farmer behavior with respect to nutrient use and management. However, few of these programs designed to change farmer behavior have been evaluated due to the lack of detailed data over an appropriate time frame. The Central Platte Natural Resources District (CPNRD) in Nebraska has identified an intensively cultivated, irrigated area with average groundwater nitrate-nitrogen (N) levels about double the EPA’s safe drinking water standard. The CPNRD implemented a joint education and regulatory N management program in the mid-1980s to reduce groundwater N. This analysis reports N use and management, yield, and groundwater nitrate trends in the CPNRD for nearly 3000 continuous-corn fields from 1989 to 1998, where producers faced limits on the timing of N fertilizer application but no limits on amounts. Groundwater nitrate levels showed modest improvement over the 10 years of this analysis, falling from the 1989–1993 average of 18.9 to 18.1 mg/l during 1994–1998. The availability of N in excess of crop needs was clearly documented by the CPNRD data and was related to optimistic yield goals, irrigation water use above expected levels, and lack of adherence to commercial fertilizer application guidelines. Over the 10-year period of this analysis, producers reported harvesting an annual average of 9729 kg/ha, 1569 kg/ha (14%) below the average yield goal. During 1989�1998, producers reported annually applying an average of 162.5 kg/ha of commercial N fertilizer, 15.7 kg/ha (10%) above the guideline level. Including the N contribution from irrigation water, the potential N contribution to the environment (total N available less estimated crop use) was estimated at 71.7 kg/ha. This is an estimate of the nitrates available for denitrification, volatilization, runoff, future soil N, and leaching to groundwater. On average, between 1989–1993 and 1994–1998, producers more closely followed CPNRD N fertilizer recommendations and increased their use of postemerge N applications � an indication of improved synchrony between N availability and crop uptake.

scholarly journals N2O Fluxes and Related Processes of Denitrification in Acidified Soil

2020 ◽  
Author(s):  
Qian Zheng ◽  
Junjun Ding ◽  
Qiaozhen Li ◽  
Chunying Xu ◽  
Wei Lin ◽  
...  
Keyword(s):  
Soil Ph ◽  
Irrigation Water ◽  
Soil Acidification ◽  
N Fertilizer ◽  
Soil Conditions ◽  
Natural Soil ◽  
Large Contribution ◽  
Total N ◽  
Mapping Approach ◽  
The Impact

Abstract In North China, high levels of N fertilizer and irrigation water are used in fields, which cause considerable N2O fluxes via several pathways, especially anaerobic denitrification. Anaerobic denitrification is regarded as an important microbial process for N2O production in soils with a low O2 level and high N and labile C availability (the typical soil conditions caused by high levels of N fertilizer and irrigation water in the field). We conducted an anaerobic incubation experiment to determine the impact of soil acidification (with a series of soil pH levels, pH 6.2, pH 7.1, and pH 8.7) on N2O source partitioning with the addition of KNO3 and glucose. Natural abundance isotope techniques and gas inhibitor technique were applied to analyze the N2O flux derived from fungal denitrification and bacterial denitrification and its isotopocule characteristics emitted from soils after the addition of NO- 3 and glucose. A mapping approach was used to obtain further insight into the N2O production processes. Our findings confirmed that soil pH strongly controlled the N2O production and reduction rates of denitrification. Soil acidification significantly increased N2O emissions varied from 0.76 mg N kg-1 for natural soil (pH 8.7), to 1.88 mg N kg-1 for pH 7.1, and to 2.35 mg N kg-1 for pH 6.2, and had a blockage effect on the reduction of N2O to N2. The addition of carbon sources promoted complete denitrification. We assumed a higher contribution of fungal denitrification to N2O production compared to total N2O emission associated with acidified soil. A promotion of the contribution of fungal denitrification-derived N2O was indeed observed with decreasing pH, increasing from 0.28 mg N kg-1 for pH 8.7 to 0.94 mg N kg-1 for pH 6.2. The addition of glucose further increased the contribution of fungal denitrification to N2O production from 0.99 mg N kg-1 for pH 8.7 to 3.66 mg N kg-1 for pH 6.2. The mapping approach provided rational results for correcting N2O reduction compared with the acetylene inhibition method. The results calculated by both methods indicated a reasonably large contribution of fungal denitrification to total N2O production in acidified soils.

scholarly journals Modelled Quantification of Different Sources of Nitrogen Inefficiency in Semi-Arid Cropping Systems

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1222
Author(s):  
Niloufar Nasrollahi ◽  
James Hunt ◽  
Caixian Tang ◽  
David Cann
Keyword(s):  
Water Conservation ◽  
Cropping Systems ◽  
C:N Ratio ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Annual Rainfall ◽  
N Availability ◽  
Application Rates ◽  
Fertilizer Application Rate ◽  
Semi Arid

Most dryland grain growers in Australia retain all or most of their crop residues to protect the soil from erosion and to improve water conservation but retaining stubbles with a high carbon-to-nitrogen (C:N) ratio can affect N availability to crops. A simulation experiment was conducted to investigate the effects of N fertilizer application rate and residue retention on soil N dynamics. The simulation used seven N fertilizer application rates (0, 25, 50, 75, 100, 150 and 200 kg N ha−1) to wheat (Triticum aestivum) over 27 years (1990–2016) at four locations across a gradient in annual rainfall in Victoria, Australia. Nitrogen immobilization, denitrification and N leaching loss were predicted and collectively defined as sources of N inefficiency. When residues were retained, immobilization was predicted to be the biggest source of inefficiency at all simulated sites at N application rates currently used by growers. Leaching became a bigger source of inefficiency at one site with low soil water-holding capacity, but only at N rates much higher than would currently be commercially applied, resulting in high levels of nitrate (NO3−) accumulating in the soil. Denitrification was an appreciable source of inefficiency at higher rainfall sites. Further research is necessary to evaluate strategies to minimize immobilization of N in semi-arid cropping systems.

scholarly journals Predicting nitrogen fertilizer requirements for corn by chlorophyll meter under different N availability conditions

2005 ◽  
Vol 85 (1) ◽  
pp. 149-159 ◽  
Author(s):  
M. T. Rashid ◽  
Paul Voroney ◽  
G. Parkin
Keyword(s):  
Management Strategies ◽  
Crop Management ◽  
Inverse Correlation ◽  
Accurate Method ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
N Availability ◽  
Corn Hybrids ◽  
Chlorophyll Meter ◽  
Application Rates

Nitrogen management strategies that enhance fertilizer use efficiency and maximize profitability in corn require a rapid and accurate method to determine the crop N needs of current hybrids. The objective of this study was to evaluate the potential of a portable chlorophyll meter for predicting N fertilizer requirements for corn grown under varying levels of N availability. Several crop management treatments were imposed in an attempt to create conditions ranging from low N availability (oily food waste application in spring and fall, application at different rates in spring) to high N availability (continuous fertilized corn, winter wheat cover crop). Different corn hybrids were sown at different sites (21 site yr) and varying N fertilizer application rates were applied. Chlorophyll meter readings (CMR) were taken at the 5th to 6th leaf stage (V6) using a SPAD-502 chlorophyll meter. The crop management treatments, corn hybrids and their interaction significantly affected the chlorophyll meter readings. A high inverse correlation between chlorophyll meter readings and maximum economic rate of nitrogen (MERN) was observed (r = −0.87). The main new and unique aspect of our research is the development of a linear model for using chlorophyll meter measurements to make N fertilizer recommendations (MERN = 348.47 − 8.5304 × CMR ) for corn production under varying degrees of N availability in Southern Ontario. Key words: Chlorophyll meter, soil organic carbon, nitrogen application

scholarly journals Physiomorphology of Soybean as Affected by Drought Stress and Nitrogen Application

Scientifica ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Oqba Basal ◽  
András Szabó
Keyword(s):  
Drought Stress ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Stress Conditions ◽  
The Other ◽  
Nitrogen Application ◽  
Total N ◽  
Affected Plant ◽  
Soybean Plants ◽  
N Demand

Drought periods are predicted to increase in the future, putting the production of sensitive crops under serious hazards. Soybean, as a legume, is capable of partly achieving its nitrogen demands through the N2-fixation process; however, this process is inhibited by drought stress conditions. Moreover, N2-fixation might not fulfill the total N demand for soybean plants, so supplemental N-fertilizer doses might be crucial. A 3-year experiment was carried out in Debrecen, Hungary, to investigate the effects of inoculation and N-fertilizer application on the physiomorphology of soybean (cv. Boglár) under both drought stress and irrigated conditions. Results showed that, regardless of inoculation, drought negatively affected plant height, LAI, SPAD, and, to a smaller extent, NDVI. On average, increasing N-fertilizer enhanced these traits accordingly. Inoculation, on the other hand, resulted in taller plants and higher LAI values, but lower SPAD values. It could be concluded that soybean’s physiomorphology is negatively influenced by drought stress and that N-fertilizer application can enhance it whether soybean plants suffer from drought stress conditions or not.

scholarly journals Nitrogen Fertilizer Management and Maize Straw Return Modulate Yield and Nitrogen Balance in Sweet Corn

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 362 ◽  
Author(s):  
Lei Gao ◽  
Wu Li ◽  
Umair Ashraf ◽  
Wenjia Lu ◽  
Yuliang Li ◽  
...  
Keyword(s):  
Sweet Corn ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Fertilizer Management ◽  
N Loss ◽  
Total N ◽  
Straw Management ◽  
Leaf Stage ◽  
Straw Return ◽  
Ear Number

Nitrogen fertilizer is an important component of crop production; however, its excessive application could result in N loss that could have serious environmental concerns. Straw incorporation in the soil after crop harvest is one of the most feasible straw management techniques, however, the optimization of nitrogen (N) fertilizer management and maize straw incorporation to modulate the crop yield and to maintain N balance in sweet corn is necessary to get better yields on a sustained basis. The present study was comprised of two straw management treatments i.e., (i) no straw return (S0), and (ii) incorporation of crushed corn ears by into the soil using rotary tiller (S100) and four N fertilizer management treatments i.e., (i) common farmer practice with total N applied at 300 kg ha−1 with 50%, 5%, 30%, and 15% splits at basal, 3-leaf stage (V3), at hilling stage (V8) and at tasseling/flowering stage (RT), respectively (FM); (ii) application of total N at 225 kg ha−1 with 40%, 10% and 50% at basal, 3-leaf stage (V3) and at hilling stage (V8), respectively (OMI); (iii) application of total N at 150 kg ha−1 with 40%, 10% and 50% at basal, 3-leaf stage (V3), and at hilling stage (V8), respectively (OMII); and (iv) the treatment without any fertilizer application (N0). The hybrid sweet corn cultivar ‘Yuetian 28’ was grown during the spring and autumn growing seasons of 2016 and 2017. The results showed that the N management treatments substantially improved the fresh ear yield, ear number and ear weight, partial factor productivity from nitrogen (PFPN), recovery efficiency from nitrogen (REN), and agronomic efficiency from nitrogen (AEN). Compared with FM, the OMI and OMII treatments significantly increased the AEN and PFPN whilst decreased the apparent N loss, however, the fresh ear yield, ear number and ear weight in OMI treatment were found to be statistically similar (p ˃ 0.05) to FM. Moreover, the S100 treatment did not affect the fresh ear yield and yield components significantly. Overall, straw return combined with an optimized N fertilizer application could improve the yield of sweet corn on a sustained basis with minimum and/or negligible N loss.

scholarly journals The effect of nitrogen and the method of application on the yield of cauliflower

1995 ◽  
Vol 43 (4) ◽  
pp. 409-418 ◽  
Author(s):  
A.P. Everaarts ◽  
C.P. De Moel
Keyword(s):  
Soil Layer ◽  
Fertilizer Application ◽  
Mineral Nitrogen ◽  
N Fertilizer ◽  
N Availability ◽  
Split Application ◽  
Band Placement ◽  
N Application ◽  
Broadcast Application ◽  
High Yields

The effects of nitrogen on cauliflower yields were studied over a period of 3 seasons at several locations. The cultivar used was Fremont in some cases and Plana in others. Different amounts of N fertilizer were applied at planting and were broadcast or band placed. Another treatment consisted of a split application. The number of plants harvested was not consistently influenced by the amount of N or the method of application. N application influenced the size of the marketable curd. At high yields, band placement had no advantage over broadcast application with regard to increasing the yield or reducing the amount of fertilizer supplied. Split application did not increase the yield and sometimes even decreased the yield. The best correlation between yield and N availability was found when the mineral nitrogen (Nmin) in the soil layer 0-60 cm at planting was taken into account. N fertilizer application was optimal when it produced an Nmin value of 224 kg/ha.

Nitrogen inputs and losses from clover/grass pastures grazed by dairy cows, as affected by nitrogen fertilizer application

1999 ◽  
Vol 132 (2) ◽  
pp. 215-225 ◽  
Author(s):  
S. F. LEDGARD ◽  
J. W. PENNO ◽  
M. S. SPROSEN
Keyword(s):  
Dairy Cows ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Organic N ◽  
Total N ◽  
Nitrogen Inputs ◽  
N Input ◽  
Maize Grain ◽  
Intensively Managed ◽  
N Pool

Nitrogen (N) inputs and outputs were measured over 3 years in a trial with four farmlets (each with 16 randomly-allocated 0·4 ha paddocks) on permanent white clover/ryegrass pastures which were grazed throughout the year by dairy cows near Hamilton, New Zealand. Three farmlets were stocked at 3·3 cows/ha and received nominal rates of N fertilizer (urea in 8–10 split applications) of 0, 200 or 400 kg N/ha per year. A fourth farmlet with 4·4 cows/ha received 400 kg N/ha per year and was supplemented with maize grain during the first two years.Nitrogen balances were calculated, with [sum ]N inputs[ape ][sum ]N outputs. Annual inputs from N2 fixation were 99–231 kg N/ha in the 0 N farmlet, but declined to 15–44 kg N/ha in the 400 N farmlets. The main N outputs (in kg N/ha per year) were in milk (72–126), nitrate leaching (20–204), and transfer of N via cow excreta from pastures to lanes and milking shed (54–92). Gaseous losses by denitrification (3–34) and volatilization (15–78) were smaller than the other N outputs but increased significantly with N fertilizer application. In the maize-supplemented farmlet, N outputs in milk were 31% higher than in the corresponding non-supplemented 400 N farmlet, whereas leaching losses averaged 17% lower during the 2 years of supplementation.In the N-fertilized farmlets, estimated N balances were influenced by inclusion of the transitional N processes of immobilization of fertilizer N into the soil organic N pool (estimated using 15N at 42–94 kg N/ha per year) and the contribution from mineralization of residual clover-fixed N in soil not accounted for in the current estimates of N2 fixation (estimated at up to 70% of measured N2 fixation or 46 kg N/ha per year). However, these processes were counteracting and together were calculated to have only a small net effect on total N balances.The output of N in products (milk, meat and feed) relative to the total N input averaged 26% in the 400 N farmlets, and is compared to that measured for commercial intensively-managed dairy farms in England and the Netherlands (14–20%). The 0 N farmlet, which was reliant on N2 fixation as the sole N input, was relatively very N-efficient with the milk production being 83% of that in the 400 N farmlet (at 3·3 cows/ha) and the N output in products relative to total N input averaging 52%.

scholarly journals A survey of irrigation water and soil quality that likely impacts paddy rice yields in Kilimanjaro, Tanzania

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Fridolin M. Mpanda ◽  
Mwemezi J. Rwiza ◽  
Kelvin M. Mtei
Keyword(s):  
Irrigation Water ◽  
Management Practices ◽  
Harmful Effect ◽  
High Standard ◽  
Fertilizer Application ◽  
Soil Samples ◽  
Paddy Rice ◽  
Nutrient Deficiencies ◽  
Total N ◽  
Rice Yields

AbstractIn this study, the impacts of irrigation water quality and soil characteristics on paddy rice yields were investigated. Standard spectroscopy and spectrometry methods were used to analyze irrigation water and irrigated soil samples. The irrigation water had sodium adsorption ratio (SAR) values ranging from 0 to 3. The corresponding electrical conductivity (EC) values were between 0.2 and 0.7 dS/m and accounted for 14% of all samples—posing slight to moderate infiltration problem. Neither Na+ nor Cl− levels were high enough to cause toxicity problems in the irrigation water. For B, 54% of the samples were found to have moderate toxicity whereas ~ 14% of the samples indicated severe B toxicity in the irrigation water. For bicarbonate, about 86 and 14% of the irrigation water indicated slight-to-moderate and severe potential detrimental effect to plant growth, respectively. All trace elements in the irrigation water were too low to cause any harmful effect. Although soil EC, organic carbon (OC), and pH indicated favorable level, there were high standard deviation (SD) values in soil Fe and Zn. The mean value of Fe in soils was 19.8 mg/kg, indicating signs of Fe-deficiency. High SD values were also found in the total N (TN) content of the studied soils. Furthermore, a low soil K content was observed in the analyzed soil samples. Appropriate fertilizer application for improving nutrient deficiencies in the study area is highly recommended. Furthermore, on-farm management practices need to be guided by scientific findings from the present as well as other studies.

scholarly journals Response of Highbush Blueberry to Nitrogen Fertilizer During Field Establishment, I: Accumulation and Allocation of Fertilizer Nitrogen and Biomass

HortScience ◽  
2012 ◽  
Vol 47 (5) ◽  
pp. 648-655 ◽  
Author(s):  
M. Pilar Bañados ◽  
Bernadine C. Strik ◽  
David R. Bryla ◽  
Timothy L. Righetti
Keyword(s):  
Ammonium Sulfate ◽  
N Uptake ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Vaccinium Corymbosum ◽  
N Fertilizer ◽  
Growth And Yield ◽  
Highbush Blueberry ◽  
Total N ◽  
Starting Point

The effects of nitrogen (N) fertilizer application on plant growth, N uptake, and biomass and N allocation in highbush blueberry (Vaccinium corymbosum L. ‘Bluecrop’) were determined during the first 2 years of field establishment. Plants were either grown without N fertilizer after planting (0N) or were fertilized with 50, 100, or 150 kg·ha−1 of N (50N, 100N, 150N, respectively) per year using 15N-depleted ammonium sulfate the first year (2002) and non-labeled ammonium sulfate the second year (2003) and were destructively harvested on 11 dates from Mar. 2002 to Jan. 2004. Application of 50N produced the most growth and yield among the N fertilizer treatments, whereas application of 100N and 150N reduced total plant dry weight (DW) and relative uptake of N fertilizer and resulted in 17% to 55% plant mortality. By the end of the first growing season in Oct. 2002, plants fertilized with 50N, 100N, and 150N recovered 17%, 10%, and 3% of the total N applied, respectively. The top-to-root DW ratio was 1.2, 1.6, 2.1, and 1.5 for the 0N, 50N, 100N, and 150N treatments, respectively. By Feb. 2003, 0N plants gained 1.6 g/plant of N from soil and pre-plant N sources, whereas fertilized plants accumulated only 0.9 g/plant of N from these sources and took up an average of 1.4 g/plant of N from the fertilizer. In Year 2, total N and dry matter increased from harvest to dormancy in 0N plants but decreased in N-fertilized plants. Plants grown with 0N also allocated less biomass to leaves and fruit than fertilized plants and therefore lost less DW and N during leaf abscission, pruning, and fruit harvest. Consequently, by Jan. 2004, there was little difference in DW between 0N and 50N treatments; however, as a result of lower N concentrations, 0N plants accumulated only 3.6 g/plant (9.6 kg·ha−1) of N, whereas plants fertilized with 50N accumulated 6.4 g/plant (17.8 kg·ha−1), 20% of which came from 15N fertilizer applied in 2002. Although fertilizer N applied in 2002 was diluted by non-labeled N applications the next year, total N derived from the fertilizer (NDFF) almost doubled during the second season, before post-harvest losses brought it back to the starting point.

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