Efficiency of Isobutylidene Diurea, Sulphur-Coated Urea and Urea Plus Nitrapyrin, compared with Divided Dressings of Urea, for Dry Matter Production and Nitrogen Uptake of Ryegrass

1987 ◽  
Vol 23 (2) ◽  
pp. 167-179 ◽  
Author(s):  
J. Halevy

SummaryTwo slow-release nitrogen fertilizers, isobutylidene diurea (IBDU) and sulphur-coated urea (SCU), and urea plus nitrapyrin were compared with urea alone for their effect on the growth and nitrogen uptake of ryegrass in a greenhouse experiment.The IBDU and the SCU were applied in one dressing before sowing and the urea in five dressings (one after each cut). Dry matter yield and nitrogen uptake of the six cuts at the optimum levels of 3 and 6 g N pot−1 (equivalent to 1120 and 2240 kg N ha−1 on a weight basis) were similar for the slow-release fertilizers and urea, showing that SCU and IBDU can be effective sources of nitrogen for ryegrass at rates far above those regarded as safe for conventional nitrogen fertilizers when applied in a single dose.Nitrapyrin at 20 ppm effectively inhibited nitrification for 12 weeks, then its effect rapidly declined, disappearing after 18 weeks. Ryegrass growth was retarded by nitrapyrin treatment, probably as a result of an accumulation of NH4-N in the soil.

1978 ◽  
Vol 18 (92) ◽  
pp. 415 ◽  
Author(s):  
KF Lowe ◽  
JF Cudmore

Three slow-release nitrogen fertilizers, urea formaldehyde, nitrogen-enriched coal (NEC) and corea (a coal-urea formulation) were compared with conventional nitrogenous fertilizers (urea, ammonium nitrate and ammonium sulphate) in a small-plot cutting experiment. The slow-release fertilizers were applied in one 672 kg N ha-1 dressing to an established Digitaria decumbens (pangola grass) pasture on wallum heath in south-east Queensland. Conventional fertilizers were applied in one, two or four applications in one, two or three years respectively, all treatments receiving a total of 672 kg N ha-1. Dry matter production, nitrogen yield and nitrogen recovery were compared over four summer periods. Over four years, pangola grass produced highest dry matter yields when fertilized with urea formaldehyde, the residual effect disappearing in the fourth summer. Annual yield distribution was equivalent to that from regular applications of conventional fertilizers. NEC released little nitrogen for grass growth in four years while corea had little effect on yield after the first summer. Nitrogen recovery from urea formaldehyde was equivalent to that from ammonium nitrate and urea (applied in four dressings of 168 kg N ha-1). Where 672 kg ha-1 of nitrogen was applied in one dressing, nitrogen recovery was in the order urea formaldehyde >> ammonium nitrate > urea >> ammonium sulphate.


2010 ◽  
Vol 34 (2) ◽  
pp. 435-442 ◽  
Author(s):  
Alberto C. de Campos Bernardi ◽  
Marisa Bezerra de Mello Monte ◽  
Paulo Renato Perdigão Paiva ◽  
Carlos Guarino Werneck ◽  
Patrick Gesualdi Haim ◽  
...  

Zeolites are hydrated crystalline aluminosilicate minerals of natural occurrence, structured in rigid third dimension net that can be used as slow release plant-nutrient source. The main objective of this study was to evaluate the effects of plant growth substrate under zeolite application, enriched with N, P and K, on dry matter yield and on nutrient contents in consecutive crops of lettuce, tomato, rice, and andropogon grass. The experiment was carried out in a greenhouse, with 3 kg pots with an inert substrate, evaluated in a randomized block design with three replications. Treatments consisted of four types of enrichment of concentrated natural zeolite: concentrated zeolite (Z) only, zeolite + KNO3 (ZNK), zeolite + K2HPO4 (ZPK) and zeolite + H3PO4 + apatite (ZP), and a control grown in substrate fertilized with a zeolite-free nutrient solution. Four levels of enriched zeolite were tested: 20, 40, 80, and 160 g/pot. Four successive crops were grown on the same substrate in each pot: lettuce, tomato, rice, and andropogon grass. Results indicated that N, P and K enriched zeolite was an adequate slow-release nutrient source for plants. The total dry matter production of above-ground biomass of four successive crops followed a descending order: ZP > ZPK > ZNK > Z.


Author(s):  
B. Balaganesh ◽  
P. Malarvizhi ◽  
N. Chandra Sekaran ◽  
P. Jeyakumar ◽  
K. R. Latha ◽  
...  

Controlled release nitrogen fertilizers could be an excellent management approach for improving nitrogen fertilizer efficiency. The present study aimed to investigate the effect of coated urea fertilizers to increase nitrogen uptake and utilization of maize. The nitrogen use efficiency of maize from various biodegradable polymer-coated urea fertilizers, such as palm stearin coated urea (PSCU), pine oleoresin coated urea (POCU), and humic acid coated urea (HACU), was determined in a pot culture experiment conducted at the Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore, during 2021. The coating materials have been coated on urea with different coating thicknesses, viz., PSCU - 5, 10, 15%, POCU – 2, 4, 6%, and HACU - 5, 10, 15%. Among all the treatments, T11: HACU 15% produced highest grain yield (72.0g plant-1) followed by T7: POCU 4% (69.7 g plant-1) and T4: PSCU 10% (69.0g plant-1). In terms of dry matter production, T10: PSCU 10% produced maximum dry matter (186.5g plant-1), followed by T11: HACU 15% (186.2 g plant-1), and T7: POCU 4% (185.3g plant-1). The nitrogen uptake by the maize plant was higher in T7: POCU 4 % (1.62g plant-1), followed by T11: HACU 15% (1.59 g plant-1) and T4: PSCU 10% (1.59g plant-1). Irrespective of treatments, the highest nitrogen utilization by the maize crop was found in T7: POCU 4% (73.9%) followed by T4: PSCU 10% (71.1%) and T11: HACU 15% (70.9%) treatments. When compared to uncoated urea fertilizer, all coated urea fertilizers outperformed uncoated urea fertilizer in terms of grain yield, dry matter accumulation, and nitrogen uptake. To improve the nitrogen use efficiency, coated urea fertilizers prove to be a promising alternative to uncoated urea fertilizers.


1969 ◽  
Vol 86 (1-2) ◽  
pp. 15-26
Author(s):  
Héber Irizarry ◽  
Ricardo Goenaga ◽  
Ulises Chardón

A 40-month experiment was conducted to re-evaluate the nitrogen fertilization recommendation for banana grown on a clayey, mixed isohyperthermic Aquic Haplohumults under rainfed conditions. Five nitrogen rates (0, 85,170, 255 and 340 kg/ha/crop) were arranged in a randomized compíete block design with three replications. The nitrogen treatments were applied with 24.4 kg/ha of phosphorus, 651,7 kg/ha of potassium, and a minor element mixture containing 22.7 kg/t of fertilizer. Treatments were applied every three months. Applications of magnesium alone were also applied between treatments at the rate of 55 kg/ha in the plant crop (PC) and 110 kg/ha in each of two ratoon crops (R1, R2). During growth and development of three crops we collected data of plant and bunch traits, green and oven-dry biomass weight, nitrogen concentration in various plant organs, and bunch marketable weight at harvest. Results showed that the rate x crop interaction was highly significant (P < 0,01) for total nitrogen uptake, and for nitrogen concentration in the leaf-lamina four months before bunch harvest, and significant (P < 0.05) for total dry matter production. Total nitrogen uptake, leaf nitrogen concentration, and total dry matter production linearly increased with increments in the nitrogen rates. Overall total nitrogen uptake and total dry matter production were always significantly higher in the R2 than in the PC, Regardless of the nitrogen rate, a significantly higher nutrient concentration was always found in the leaf-lamina of the R1 plants than in either the PC or the R2 plants. Crop had no significant effect on yield, but nitrogen rate significantly influenced yield. A maximum yield of 57,060 kg/ ha/crop was obtained with an estimated nitrogen application of 240 kg/ha. This amount corresponded to a leaf nitrogen concentration of between 2.75 and 2.85 g/kg. Since the maximum yield for all crops was obtained with a nitrogen application of only 240 kg/ha, we concluded that the linear response to fertilization in excess of this amount for total nitrogen uptake, nutrient concentration, and total dry matter production may be attributed to luxury consumption of nitrogen.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 538b-538
Author(s):  
W.E. Bendixen ◽  
B.R. Hanson

Strawberries in the Santa Maria Valley are grown on beds 25.2 cm wide with four rows of strawberries and two lateral drip tapes. Previous strawberry production was on beds 15.7 cm wide with two rows of strawberries and one lateral drip tape. The two strawberry production systems were evaluated on several grower fields for water emission uniformity, soil moisture, and soil salinity. The salinity was evaluated for placement in the bed, type of salts, and nitrate concentration. At one side, the effect of banded slow-release nitrogen fertilizers as a source of nitrogen in addition to that applied through fertigation was investigated. Results showed that the EUs ranged between 80% and 96%, with an average of 89%. A variety of distributions were found for soil moisture, soil salinity, and soil nitrate, depending on the water and fertilizer management and time of sampling with respect to irrigation and fertigation. Distributions of soil moisture content made 3 to 4 days after an irrigation indicated excessive drying of the soil between irrigations. Distributions of soil salinity revealed high salt concentrations near the drip tape, where leaching was insufficient, and relatively low concentrations near the tape, where leaching was adequate. Nitrate concentrations in and below the rootzone were smaller where no slow-release fertilizers were used.


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