Ammonia Volatilization from Soil,Dry-Matter Yield,and Nitrogen Levels of Italian Ryegrass

Nitrogen (N) loss by ammonia (NH₃) volatilization is the main factor for poor efficiency of urea fertilizer applied to the soil surface. Losses can be suppressed by addition of zeolite minerals to urea fertilizer. The objective of this study was to evaluate ammonia volatilization from soil and dry-matter yield and nitrogen levels of Italian ryegrass. A greenhouse experiment was carried out with the treatments of urea, urea incorporated into soil, urea + urease inhibitor, urea + zeolite, ammonium nitrate, and unfertilized treatment. Ammonia was captured by a foam absorber with a polytetrafluoroethylene tape. There were few differences between zeolite and urease inhibitor amendments concerning NH₃ volatilization from urea. Results indicate that zeolite minerals have the potential to improve the N-use efficiency and contributed to increasing N uptake. Zeolite and urea mixture reduced 50% the losses by volatilization observed with urea.     

Comparative Efficiency of Nitrogen Sources for Lowland Rice Production

Rice (Oryza sativa L.) is the staple food for more than 50% world population and nitrogen (N) is one of the most yield-limiting nutrients for rice production worldwide. A greenhouse experiment was conducted to evaluate the efficiency of three N sources for lowland rice production. The N sources used were ammonium sulfate, common urea, and polymer-coated urea. There were three N rates, i.e. 100, 200, and 400 mg N kg^?1 applied with three sources plus one control treatment (0 mg N kg^?1). Growth, yield, and yield components were significantly increased either in a linear or quadratic fashion with the addition of N fertilizers in the range of 0–400 mg kg^?1 soil. Maximum grain yield was obtained with the addition of ammonium sulfate at 100, 200, and 400 mg kg^?1 of soil. Common urea and polymer-coated urea were more or less similar in grain production at 100 and 200 mg N kg^?1. However, at 400 mg N kg^?1 treatments, polymer-coated urea produced the lowest grain yield. Most of the growth and yield components were positively related to grain yield, except spikelet sterility which was negatively related to grain yield. Nitrogen use efficiency decreased with increasing N rate in all the three N sources. Maximum N use efficiency was obtained with the addition of ammonium sulfate at lower as well as at higher N rates compared with other two N sources.     

Effect of Salinity and Nitrogen Application on Growth,Chemical Composition and Some Biochemical Indices of Pistachio Seedlings (Pistacia Vera L.)

To study the effect of nitrogen and salinity on growth and chemical composition of pistachio seedlings (cv. ‘Badami’), a greenhouse experiment was conducted. Treatments consisted of four salinity levels [0, 800, 1600, and 2400 mg sodium chloride (NaCl) kg^?1 soil], and four nitrogen (N) levels (0, 60, 120, and 180 mg kg^?1 soil as urea). Treatments were arranged in a factorial manner in a completely randomized design with three replications. The highest level of nitrogen and salinity decreased leaf and root dry weights. Nitrogen application significantly increased the concentration of shoot N and salinity suppressed shoot N concentration. Salinity and nitrogen fertilization increased shoot and root sodium (Na), calcium (Ca), and magnesium (Mg) concentrations. Nitrogen application increased proline concentration and reducing sugar content. Although salinity levels increased proline concentration a specific trend on reducing sugars content was not observed.     

Ammonia Volatilization from Exposed Soil and Tanzania Grass Pasture Fertilized with Urea and Zeolite Mixture

The aim of this study was to evaluate the effects of a zeolite and urea mixture on ammonia volatilization. Two experiments were carried out: a greenhouse pot experiment and a field trial with Tanzania grass pasture. The pot experiment used five zeolite ratios (0, 12.5, 25, 50, and 100 percent relative to the N-urea level used) mixed with 100 kg ha^?1 of nitrogen (N). The field trial used four treatments: 0, 12.5, 25, and 50 percent of zeolite, at the dose of 50 kg ha^?1. In the greenhouse experiment, the smallest losses by volatilization occurred at the proportions of 25 percent and 100 percent. During the summer, the mixture of 25 percent of zeolite in N-urea led to a reduction in ammonia volatilization from 33.5 to 7.6 kg ha^?1. However, in the winter, volatilization was very low, and there were no differences between the treatments. The addition of 25 percent of zeolite in urea was the most appropriate relation.     

Nitrous Oxide Emissions in Response to ESN and Urea Application in a No-Till Barley Cropping System

We investigated the effect of environmentally smart nitrogen (ESN) fertilizer on nitrous oxide (N₂O) emissions under no-till barley (Hordeum vulgare L.) production over 3 years at three sites in Alberta, Canada. Treatments included two barley cultivars, with ESN and urea applied at 1× and 1.5× the recommended rate, and herbicide at 50% and 100% of registered in-crop rates. Cumulative N₂O emissions over the growing season were low (0.11 to 1.32 kg nitrogen (N) per hectare or 0.05–0.22 g N kg^?1 grain yield), and not affected by barley cultivars or herbicide rates in all nine site-years, nor by fertilizer type or rate in seven out of nine site-years. However, average N₂O emissions from ESN were 15% lower (P = 0.05) than urea across all site-years. Our results suggest ESN could play a role in reducing N₂O emissions, but the reduction will depend on rainfall events and crop N utilization.     

Assessment of urea coated with pomegranate fruit powder as N slow-release fertilizer in maize

It has been hypothesized that plant polyphenol plus lignin, cellulose, and hemicelluloses can immobilize/remineralize inorganic fertilizers, such as urea, better than polyphenol alone. To test this hypothesis, urea was coated with pomegranate (Punica granatum L.) fruit powder (containing polyphenol+lignin+cellulose) at rates of 0%, 30%, 70%, and 100% (w/w) of fertilizer urea. Fertilizer nitrogen was applied at 100 and 200 mg kg^?1 soil in a clay loam soil. This natural coating material, particularly at the rate of 100% (w/w), improved the distribution of mineral nitrogen (N) and available phosphorus (P) in soil during both early and advanced growth stages of maize and significantly increased total crop N and P uptake at both rates of fertilizer nitrogen compared to urea alone. The results suggest that urea coated with the powder of pomegranate fruit could potentially be an N slow-release fertilizer for use in better synchronizing crop N demand with soil N supply.     

Field-Scale Evaluation of Calcium Ammonium Nitrate,Urea, and Urea Treated with N-(N-Butyl) Thiophosphoric Triamide Applied to Grassland in Ireland

This study investigated the effects of nitrogen (N) source, rate, and timing of application on dry-matter yield (DMY), N responses, N uptake and N-use efficiency (NUE) in a grass crop. The experiment used three fertilizer treatments: calcium ammonium nitrate (CAN), urea, and urea treated with N-(n-butyl) thiophosphoric triamide (NBTPT), applied at 0 (control), 25, 50, and 75 kg ha^?1 of N over eighteen application timings. Results showed relatively lower agronomic performance of urea compared with CAN when applied in early spring. Urea reported lower N responses, lower relative DMY (90 percent), and relative N uptake (85 percent), which translated in lower NUE (0.45 kg kg^?1) compared with CAN (0.70 kg kg^?1). In spring fertilizer applications, urea and NBTPT showed DMY and NUE values comparable to those obtained with CAN. However, NBTPT enhanced overall performance of urea, which was shown with increasing temperatures toward summer or increasing N application rates. For summer applications, the efficiency of urea was less (P < 0.05) than that of CAN or NBTPT in all measured parameters, suggesting greater ammonia volatilization loss in urea-treated grass. Nitrogen saved in volatilization improved uptake and responses in NBTPT-treated grass, and hence DMY was not affected compared with CAN in summer fertilizer applications. The results of this study are supportive of increased usage of urea-based fertilizers treated with NBTPT.     

Controlled‐release urea decreased ammonia volatilization and increased nitrogen use efficiency of cotton

Excessive nitrogen (N) fertilizer input leads to higher N loss via ammonia (NH₃) volatilization. Controlled‐release urea (CRU) was expected to reduce emission losses of N. An incubation and a plant growth experiment with Gossypium hirsutum L. were conducted with urea and CRU (a fertilizer mixture of polymer‐coating sulfur‐coated urea and polymer‐coated urea with N ratios of 5 : 5) under six levels of N fertilization rates, which were 0% (0 mg N kg⁻¹ soil), 50% (110 mg N kg⁻¹ soil), 75% (165 mg N kg⁻¹ soil), 100% (220 mg N kg⁻¹ soil), 125% (275 mg N kg⁻¹ soil), and 150% (330 mg N kg⁻¹ soil) of the recommended N fertilizer rate. For each type of N fertilizer, the NH₃ volatilization, cotton yield, and N uptake increased with the rate of N application, while N use efficiency reached a threshold and decreased when N application rates of urea and CRU exceeded 238.7 and 209.3 mg N kg⁻¹ soil, respectively. Ammonia volatilization was reduced by 65–105% with CRU in comparison to urea treatments. The N release characteristic of CRU corresponded well to the N requirements of cotton growth. Soil inorganic N contents, leaf SPAD values, and net photosynthetic rates were increased by CRU application, particularly from the full bloom stage to the initial boll‐opening stage. As a result, CRU treatments achieved significantly higher lint yield by 7–30%, and the N use efficiency of CRU treatments was increased by 25–124% relative to that of urea treatments. These results suggest that the application of CRU could be widely used for cotton production with higher N use efficiency and lower NH₃ volatilization.     

Effect of Raw and NH4+-enriched Zeolite on Nitrogen Uptake by Wheat and Nitrogen Leaching in Soils with Different Textures

Leaching of nutrients in soil can change the surface and groundwater quality. The present study aimed at investigating the effects of raw and ammonium (NH₄⁺)-enriched zeolite on nitrogen leaching and wheat yields in sandy loam and clay loam soils. The treatments were one level of nitrogen; Z₀: (100 kg (N) ha^?1) as urea, two levels of raw zeolite; Z₁:(0.5 g kg^?1 + 100 kg ha^?1) and Z_2: (1 g kg^?1 + 100 kg ha^?1), and two levels of NH₄⁺-enriched zeolite; Z₃: (0.5 g kg^?1 + 80 kg ha^?1) and Z₄: (1 g kg^?1 + 60 kg ha^?1). Wheat grains were sown in pots and, after each irrigation event, the leachates were collected and their nitrate (NO₃^?) and NH₄⁺ contents were determined. The grain yield and the total N in plants were measured after four months of wheat growth. The results indicated that the amounts of NH₄⁺ and NO₃^? leached from the sandy loam soil were more than those from the clay loam soil in all irrigation events. The maximum and minimum concentrations of nitrogen in the drainage water for both soils were observed at control and NH₄⁺-zeolite treatments, respectively. Total N in the plants grown in the sandy loam was higher compared to plants grown in clay loam soil. Also, nitrogen uptake by plants in control and NH₄⁺-zeolite was higher than that of raw-zeolite treatments. The decrease in the amount of N leaching in the presence of NH₄⁺-zeolite caused more N availability for plants and increased the efficiency of nitrogen fertilizers and the plants yield.     

Efficiency of Foliar Versus Granular Fertilization: A Field Study of Creeping Bentgrass Performance

ABSTRACT

Limited information comparing foliar versus granular fertilization of turfgrasses is available. The objective of this research was to evaluate liquid and/or granular N fertilization on turfgrass quality, clipping yield, and root biomass of ‘L-93’ creeping bentgrass. Treatments consisted of two annual nitrogen (N) inputs, 127 and 190 kg ha^?1, using 100% granular urea fertilizer, 50% granular urea + 50% liquid urea fertilizer, or 100% liquid urea fertilizer. These results suggest a rate of at least 190 kg N ha^?1 yr^?1 is needed to maintain acceptable bentgrass quality in the transition zone of the U.S. Combining both liquid and granular methods appear superior compared to relying on one method exclusively.     

Evaluation of the Nitrification Inhibitor 3,4-Dimethylpyrazole Phosphate in Two Chilean Soils

ABSTRACT

Two Chilean soils were used to evaluate the performance of the nitrification inhibitor 3,4-dimetilpirazol phosphate (DMPP) added to ammonium-sulfate-nitrate (ASN) in comparison with traditional nitrogen (N) sources and different N-application forms. Two experiments were conducted: In the first, broccoli (Brassica oleracea var. italica) plants were cultivated in pots under greenhouse conditions, and received a N-fertilization equivalent to 150 Kg N ha^?1 as ASN+DMPP (one application), urea (two splits), and sodium-potassium nitrate (three splits). In the second, ryegrass (Lolium spp.) plants were grown in pots under shading conditions. In this case, ASN+DMPP and urea were applied at N rates equivalent to 150 and 300 Kg N ha^?1 in a single application. In the first experiment, ASN+DMPP increased dry-matter production, maintained a higher N content in the soil (at least until the middle of the growing period), and improved fertilizer N-use efficiency (FUE) in one soil. There were no significant differences in N-leaching losses. In the ryegrass experiment, ASN+DMPP increased dry-matter production and FUE, while N-leaching losses were reduced. Treatments with ASN+DMPP maintained higher N levels in soil throughout the growing period, and there were no significant differences in the available N fraction between the two N rates. The use of DMPP-containing fertilizers may be a good alternative for increasing FUE.     

Nitrogen,Potassium, and Nitrate Concentrations of Lettuce Grown in a Substrate with KNO3-Enriched Zeolite

Zeolite minerals improve the efficiency of nutrient use by plants by helping to regulate the release of nitrogen and nitrate accumulation in tissues. The main objectives of this research were to evaluate effects of the addition of zeolite enriched with potassium nitrate (KNO₃) on the nitrate (NO₃-N) and potassium (K) levels of lettuce shoot. Treatments arranged in a completely randomized block design with three replications comprised two types of the natural zeolite: concentrated zeolite, zeolite + KNO₃, and a control grown in substrate fertilized with a nutrient solution without zeolite supply. Four levels of enriched zeolite were tested (20, 40, 80, and 160 g per pot). Nitrogen, K, and NO₃-N data were evaluated and response equations were fitted. The results indicated that zeolite enriched with KNO₃ released the macronutrients N and K to lettuce plants. The concentrations of total N, total K, and NO₃-N increased with zeolite levels, and there was a positive correlation between total N and NO₃-N forms. To keep levels of NO₃-N^? in shoots within the safe limit for human consumption, based upon the regression equation for NO₃-N the recommended dose of KNO₃-enriched zeolite should be up to 78 g per plant.     

Reducing ammonia loss from urea and improving soil-exchangeable ammonium retention through mixing triple superphosphate, humic acid and zeolite

Ammonia losses from soil following fertilization with urea may be large. This laboratory study compared the effect of four different, urea–triple superphosphate (TSP)–humic acid–zeolite, mixtures on NH₃ loss, and soil ammonium and nitrate contents, with loss from surface‐applied urea without additives. The soil was a sandy clay loam Typic Kandiudult (Bungor Series). The mixtures significantly reduced NH₃ loss by between 32 and 61% compared with straight urea (46% N) with larger reductions with higher rates of humic acid (0.75 and 1 g kg^?1 of soil) and zeolite (0.75 and 1 g kg^?1 of soil). All the mixtures of acidic P fertilizer, humic acid and zeolite with urea significantly increased soil NH₄ and NO₃ contents, increased soil‐exchangeable Ca, K and Mg, and benefited the formation of NH₄ over NH₃ compared with urea without additives. The increase in soil‐exchangeable cations, and temporary reduction of soil pH may have retarded urea hydrolysis in the microsite immediately around the fertilizer. It may be possible to improve the efficiency of urea surface‐applied to high value crops by the addition of TSP, humic acid and zeolite.     

EFFECT OF NITROGEN SOURCES AND RATES ON YIELD AND QUALITY OF SILAGE CORN

The objective of this study was to determine the effect of nitrogen (N) application source and rate on silage corn (Zea mays L.). Urea, ammonium nitrate, and ammonium sulfate were compared at 50, 100, 150, and 200 kg N ha^?1. The application of ammonium sulfate produced the highest plant height, leaf area index (LAI), total yield, and stem, leaf, and ear dry matter, followed by ammonium nitrate and urea. However, nitrogen sources had no marked effects on the content of protein, ash, oil, soluble carbohydrates, acid detergent fiber (ADF) and neutral detergent fiber (NDF). As the rate of nitrogen increased plant height, LAI, total yield, and stem, leaf, tassel, and ear dry matters, and protein, ash and oil contents increased while soluble carbohydrates, ADF, and NDF contents decreased. Ammonium sulfate was the most effective N source on production and 200 kg N ha^?1 was the most effective N rate on corn yield and quality.     

Experimental Study on the Effects of Natural Zeolite on Lead Toxicity,Growth, Nodulation,and Chemical Composition of Soybean

Lead (Pb) is one of the most dangerous contaminants that has been released into the environment over many years by anthropogenic activities. In the present study, the effect of zeolite on the Pb toxicity, growth, nodulation, and chemical composition of soybean (Glycine max L. var. Williams) was evaluated. Treatments consisted of factorial combination of three levels of zeolite (0, 2, and 5 g kg^?1) and three levels of Pb (0, 10, and 25 mg kg^?1) with three replicates in a completely randomized design. Lead application decreased shoot and root dry weights. Without any use of Pb, addition of zeolite increased shoot dry weight, iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations and the number and dry weight of root nodules. Moreover, the greatest value for these parameters was obtained by greatest level of zeolite application (5 g zeolite kg^?1 soil). It is suggested that zeolite has positive effects on growth and chemical composition of soybean and reduces Pb toxicity in plant parts.     

RESPONSE OF MAIZE GROWN IN AN ALFISOL OF SRI LANKA TO INOCULANTS OF PLANT GROWTH PROMOTING RHIZOBACTERIA

Field experiments were conducted to assess the ability of rhizobacterial inoculants to enhance growth and yield of maize. Performances of two phosphorus (P)-solubilizing bacteria in combination with a fertilizer mixture containing rock phosphate and triple super phosphate (PFM), and five diazotrophs combining either with 150 kg or 100 kg nitrogen (N) ha^?1 supplied as urea were compared with non-inoculated-fertilized controls. Shoot P and N and soil available P and N contents were assessed and shoot biomass and ear weights were recorded at harvest. Pseudomonas cepacia resulted in significantly higher available P (51 mg P kg^?1 soil), P accumulation (3.6 g kg^?1 dry matter) and 13% increase in shoot biomass over control. Azospirillum sp. and dual inoculant comprising Enterobacter agglomerans + Agrobacterium radiobacter led to significantly higher available N (74–94 mg kg^?1 soil) and 19 to 26% increase in shoot biomass over the control. However, inoculants did not increase the yield significantly.     

Subsequent nitrogen utilisation and soil water distribution as affected by forage radish cover crop and nitrogen fertiliser in a corn silage production system

Forage radish is a unique winter cover crop that is relatively new but becoming rapidly adopted in temperate, humid North America. Little is known about how the use of this cover crop may influence subsequent nitrogen availability, soil water accumulation in the soil profile in corn silage production system. In this present work, the average nitrogen uptake by silage corn increased significantly by 11.6% in cover plots compared with the no-cover control plots. The recovery efficiency and agronomic efficiency of applied nitrogen in silage corn declined in cover plots compared to no-cover plots. The average soil water storage in cover plots was significantly higher than in the control after corn sowing and at the harvest stage. With increasing nitrogen application level, the average corn grain yield increased significantly at 56 and 112 kg N ha^?1 by 13.1% and 39.8%, respectively. Planting a forage radish cover crop can facilitate growth of silage corn and markedly improve total nitrogen uptake of corn. Consideration should be given to nitrogen application rate and also to avoiding excessive nitrogen input in the subsequent crop following a cover crop, thereby truly improving subsequent fertiliser use efficiency.     

Zeolite influences on nitrate leaching,nitrogen-use efficiency,yield and yield components of canola in sandy soil

With regard to the low cation-exchange capacity and large saturated hydraulic conductivity of sandy soils, a field experiment was carried out in 2006–2007 to determine the impact of zeolite on nitrogen leaching and canola production. Four nitrogen (N) rates (0, 90, 180, and 270 kg ha^–1) and three zeolite amounts (3, 6 and 9 t ha^?1) were included as treatments. The results demonstrated that the highest growth parameters and seed yield were attained with 270 kg N ha^?1 and 9 t zeolite ha^?1. However, the highest and the lowest seed protein percentage and oil content were obtained with 270 kg N ha^?1 accompanied by 9 t zeolite ha^?1, respectively. Nitrate concentration in drained water was affected by nitrogen and zeolite. The lowest and highest leached nitrate values were found in control without N and zeolite (N₀Z₀) and in treatments with the highest N supply without zeolite (N₂₇₀Z₀), respectively. In general, nitrogen-use efficiency decreased with an increase in N supply. Application of 9 t zeolite ha^?1 showed higher nitrogen use efficiency than other zeolite amounts. Also, application of more N fertilizer in soil reduced nitrogen uptake efficiency. In total, application of 270 kg N ha^?1 and 9 t zeolite ha^?1 could be suggested as superior treatment.     

Effect of the Application of Biochar on Selected Soil Chemical Properties,Corn Grain,and Biomass Yields in Iowa

Biochar is a co-product of pyrolysis. To find the effects of biochar on crop production, a field study was conducted in 2007, 2008, and 2009. Treatments were arranged in a split-plot design. The main plot treatments were biochar at rates of 0, 4.5, 18 Mg ha^?1. Sub-plot treatments were nitrogen (N) rates of 0, 56, 112, 224 kg N ha^?1 as urea (46–0–0). These treatments were applied to a continuous corn cropping system. Soil samples were planned to be taken during the first eight weeks of the growing season and after harvest to measure ammonium–N (NH₄ ⁺–N) and nitrate–N (NO₃ ^?–N). Nitrogen in the plant and grain was measured along with grain yield and plant biomass. There was no difference in the yield due to the addition of biochar or the interaction of biochar and N fertilizer, but there were differences due to the N fertilizer alone.     

Developing nitrogen management strategies under drip fertigation for wheat and maize production in the North China Plain based on a 3‐year field experiment

The intensive winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) cropping systems in the North China Plain (NCP) rely on the heavy use of mineral nitrogen (N) fertilizers. As the fertigated area of wheat and maize in the NCP has grown rapidly during recent years, developing N management strategies is required for sustainable wheat and maize production. Field experiments were conducted in Hebei Province during three consecutive growth seasons in 2012–2015 to assess the influence of different N fertigation rates on N uptake, yield, and nitrogen use efficiency [NUE: recovery efficiency (RE_N) and agronomic efficiency (AE_N)]. Five levels of N application, 0 (FN₀), 40 (FN_40%), 70 (FN_70%), 100 (FN_100%), and 130% (FN_130%) of the farmer practice rate (FP: 250 kg N ha^?1 and 205.5 kg N ha^?1 for wheat and maize, respectively), corresponding to 0, 182.2, 318.9, 455.5, and 592.2 kg N ha^?1 y^?1, respectively, were tested. Nitrogen in the form of urea was dissolved in irrigation water and split into six and four applications for wheat and maize, respectively. In addition, the treatment “drip irrigation + 100% N conventional broadcasting” (DN_100%) was also conducted. All treatments were arranged in a randomized complete block design with three replications. The results revealed the significant influence of both N fertigation rate and N application method on grain yield and NUE. Compared to DN_100%, FN_100% significantly increased the 3‐year averaged N recovery efficiency (RE_N) by 0.09 kg kg^?1 and 0.04 kg kg^?1, and the 3‐year averaged N agronomic efficiency (AE_N) by 2.43 kg kg^?1 and 1.62 kg kg^?1 for wheat and maize, respectively. Among N fertigation rates, there was no significant increase in grain yield in response to N applied at a greater rate than 70% of FP due to excess N accumulation in vegetative tissues. Compared to FN_70%, FN_100%, and FN_130%, FN_40% increased the RE_N by 0.17–0.57 kg kg^?1 and 0.03–0.34 kg kg^?1and the AE_N by 4.60–27.56 kg kg^?1 and 2.40–10.62 kg kg^?1 for wheat and maize, respectively. Based on a linear‐response relationship between the N fertigation rate and grain yield over three rotational periods it can be concluded that recommended N rates under drip fertigation with optimum split applications can be reduced to 46% (114.6 kg N ha^?1) and 58% (116.6 kg N ha^?1) of FP for wheat and maize, respectively, without negatively affecting grain yield, thereby increasing NUE.