Deep Placement Of Nitrogen Fertilizers Research Articles

N2O and CO2 Emissions from Bare Soil: Effect of Fertilizer Management

The paper presents the results of a laboratory experiment focused on the assessment of the effect of different methods of application of ammonium nitrate (TD—top dressing and DP—deep placement) on N2O and CO2 emissions from soil without crop cover. Nitrogen application increased soil N2O–N fluxes by 24.3–46.4%, compared to untreated soil (NIL). N2O–N emissions from TD treatment were higher by 12.7%, compared to DP treatment. Soil CO2–C fluxes from DP treatment were significantly higher by 17.2%, compared to those from NIL treatment. Nonetheless, the differences between soil CO2–C fluxes from DP and TD treatments, as well as from TD and NIL treatments, were of no statistical significance. The cumulative greenhouse gas (GHG) emissions (a sum of cumulative soil emissions of CO2–C and N2O–N after conversion to the equivalent of CO2–C) from both N-fertilized soils were similar, and higher by 20% than from untreated soil. The obtained data show that the effect of reduction of N2O–N soil emissions gained by deep placement of nitrogen fertilizer was completely lost through an increase in CO2–C emissions from the soil. This suggests that deep placement of nitrogen fertilizers in sandy soil without crop cover might not lead to a mitigation of soil GHG emissions.

Study of nitrogen use efficiency and yield of rice influenced by deep placement of nitrogen fertilizers

Continuous increase of nitrogen fertilizer use adversely affecting the soil health as well as the environment. It necessitates the systematic study of the impact of nitrogen (N) fertilizer use-reduction on crop yield. In this article, the effects of deep placement of nitrogen fertilizers on nitrogen use efficiency (NUE) and yield of rice variety “BRRI dhan46” were investigated and compared for three N formulations: urea super granule (USG), NPK briquettes and prilled urea (PU). The experiment was conducted in randomized complete block design (RCBD) with eight N treatments replicated three times. The treatments were applied by varying doses (0, 52, 78 and 104 kg ha-1) of nitrogen fertilizers in a known identical soil and weather condition. Applications of PU, USG and NPK briquettes exhibited significant differences on yield attributes of rice. Results revealed maximum grain yield of 6.391 t ha-1 (54% increases over control) for the dose USG 104 kg ha-1 which is statistically similar to the dose USG 78 kg ha-1 and NPK briquettes 104 kg ha-1. The deep placement of USG and NPK briquettes enhanced both the recovery of applied N and N use efficiency compared to broadcast application of prilled urea. However, USG 78 kg ha-1 showed maximum apparent N recovery, N use efficiency, gross margin and marginal benefit-cost ratio. Thus, an application of 78 kg ha-1 USG can be recommended for profitable cultivation of rice variety BRRI dhan46.
 SAARC J. Agri., 17(1): 93-103 (2019)

Effect of the Nitrification Inhibitor 3,4-Dimethylpyrazole Phosphate on the Deep Placement of Nitrogen Fertilizers for Soybean Cultivation

The deep placement of urea fertilizer (DMU) containing 1% (W/W) of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on soybean growth and seed yield was as effective as those of the coated urea (CU) and lime nitrogen (LN) in a field research. The average seed yields were high in LN (464 g·m−2) and DMU (461 g·m−2) and relatively low in CU (405 g·m−2), U (396 g·m−2), and Cont (373 g·m−2) treatments. The accumulations of dry matter and nitrogen in soybean shoots were higher in the plants with deep placement of CU, LN, and DMU than U and Cont. The daily nitrogen fixation activity and daily nitrogen absorption rate were calculated based on the relative ureide method. Both nitrogen fixation activity and nitrogen absorption rate were higher in DMU, CU, and LN compared with control treatment, suggesting that the deep placement of DMU did not repress nitrogen fixation. Soil incubation test was performed using the same field soil with DMU, U, LN, and urea with DMPP 1%, 2%, and 4%. DMU inhibits nitrification similar to the pattern of LN until 8 weeks. The increasing DMPP concentration did not markedly increase the nitrification inhibition. From these results, it was concluded that urea fertilizer with 1% DMPP is efficient for deep placement of N fertilizer for soybean cultivation due to its lower price compared with CU and LN.

Efficacy of Deep Placement of Nitrogen Fertilizers on N Use Efficiency and Yield of Boro Rice (cv. BRRI Dhan29)

The efficiency of nitrogen (N) fertilizers in rice culture is low due to their losses in different ways. An experiment was, therefore, conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season of 2016 to evaluate the effect of deep placement of N fertilizers on N use efficiency and yield of BRRI dhan29 under alternate wetting and drying (AWD) condition. The soil was silt loam in texture having pH 6.07, organic matter content 1.10%, total N 0.055%, available P 3.6 ppm, exchangeable K 0.22 me% and available S 11.76 ppm. The experiment was laid out in a randomized complete block design with three replications. There were eight treatment combinations including T1 (Control), T2 (PU, 130 kg N/ha), T3 (USG, 130 kg N/ha), T4 (USG, 104 kg N/ha), T5 (USG, 78 kg N/ha), T6 (NPK briquette, 129 kg N/ha) and T7 (NPK briquette, 102 kg/ha) and T8 (NPK briquette, 78 kg N/ha). All the treatments except T6, T7 and T8 received 25 kg P and 64 kg K /ha as TSP and MoP, respectively. Treatments T6, T7, T8 received NPK briquette fertilizer. Prilled urea (PU) was applied in three equal splits. Urea super granule (USG) and NPK briquettes were applied at 10 day after transplanting (DAT) and the briquettes were placed at 8-10 cm depth in the centre of four hills in alternate rows. The results demonstrate that all the yield components except 1000-grain weight responded significantly to the deep placement of N fertilizers in the form of USG and NPK briquette. The grain and straw yields of BRRI dhan29 were also influenced significantly due to deep placement of N fertilizers under AWD condition. The highest grain yield (6163 kg/ha) was recorded for T3 [USG, 130 kg N/ha) which was statistically similar with T4 (USG, 104 kg N/ha). The highest straw yield (6415 kg /ha) was also found in T3 [USG, 130 kg N/ha]. The lowest grain yield (3266 kg/ha) and straw yield (3637 kg/ha) were found in T1 (Control). The N uptake by BRRI dhan29, N use efficiency and apparent N recovery also showed significant response to the application of PU, USG and NPK briquettes. The maximum N use efficiency of 28.88% was noted in T5 followed by T4 with the value of 26.46% and the minimum value of 17.55% was observed in T2. The results revealed that the deep placement of N fertilizers accelerated the N uptake, N recovery and N use efficiency by BRRI dhan29. Based on grain yield and cost-benefit analysis, it can be concluded that application of 130 kg N/ha as USG is useful for the profitable cultivation of boro rice, BRRI dhan29.

Effect of deep placement of nitrogen fertilizers on rice yield and N use efficiency under water regimes

The experiments were conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season of 2013 to evaluate the effect of deep placement of nitrogen (N) fertilizers on rice yield and N use efficiency under two different water regimes [continuous flooding (CF) and alternate wetting and drying (AWD)]. After deep placement of USG and NPK briquettes and each split application of PU, the water samples were collected for five consecutive days and analyzed for ammonium-Nitrogen (NH4-N) concentration. In both water regimes the floodwater NH4-N concentration gave highest value at the second day of PU application followed by gradual decrease with time and in continuous flooding condition the release of NH4-N was higher compared to AWD condition. Deep placement of N fertilizers also increased grain yield under AWD compared to CF condition and the maximum value was obtained in treatment T5 [USG 78 kg N ha-1 + PM 3 t ha-1] statistically similar to T3 [USG, 156 kg N ha-1]. Due to application USG and NPK briquettes, the N uptake and N use efficiency also gave higher values in AWD compared to CF condition. The results revealed that the deep placement of USG with poultry manure performed better in terms yield, N uptake and N use efficiency by BRRI dhan29 under AWD condition. So, the deep placement of USG under AWD condition could be recommended for higher production of boro rice.SAARC J. Agri., 13(2): 161-172 (2015)

Deep placement of nitrogen fertilizers reduces ammonia volatilization and increases nitrogen utilization efficiency in no-tillage paddy fields in central China

Deep placement of nitrogen fertilizer affects the fate of fertilizer nitrogen through influencing nitrogen transformation. Few studies have examined ammonia (NH3) volatilization and nitrogen-utilization efficiency under deep placement of nitrogen fertilizers in no-tillage (NT) paddy fields. Therefore, a field experiment was conducted to investigate the different application methods of nitrogen fertilizers [no fertilizer, traditional nitrogen broadcasting (S), and point deep placed at 5cm, 10cm and 20cm depths as basal fertilizer + nitrogen broadcasting as topdressing (e.g., 5D, 10D and 20D)] on NH3 volatilization, nitrogen recovery efficiency (NRE), nitrogen partial factor productivity (NPFP), nitrogen agronomic efficiency (NAE), and grain yield in NT paddy fields during the 2012–2013 rice growing seasons in central China. Nitrogen deep placement significantly decreased mean floodwater pH by 2–4% and mean floodwater NH4+–N concentration by 29–98% compared with nitrogen broadcasting. Nitrogen deep placement treatments significantly decreased cumulative NH3 volatilization by 20–45% in 2012 and by 15–40% in 2013 compared with S treatment. On average, nitrogen deep placement treatments significantly increased NRE by 26–93%, NPFP by 10–16%, NAE by 31–51%, and grain yield by 5–11% in both seasons compared with S treatment. In addition, 10D treatment showed the highest nitrogen utilization efficiency and grain yield, implying that this measure can be effective in increasing agricultural economic viability and decreasing NH3 volatilization. However, given high labor requirement for manual deep placement, developing mechanical fertilization technology is necessary to overcome this difficulty in future.

Floodwater Nitrogen, Rice Yield and N Use Efficiency as Influenced by Deep Placement of Nitrogenous Fertilizers

An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during the Aus season of 2012 to investigate the effects of deep placement of nitrogen (N) fertilizers on floodwater NH4-N concentration, rice yield and N use efficiency under alternate wetting and drying (AWD) condition. The experiment was laid out in a randomized complete block design with three replications. There were eight treatment combinations viz. T 1 (Control), T 2 [52 kg N from Urea super granule (USG)], T 3 (104 kg N from USG), T 4 [78 kg N from prilled urea (PU)], T 5 (120 kg N from PU), T 6 (51 kg N from NPK briquette), T 7 (78 kg N from USG) and T 8 (78 kg N from NPK briquette). The results regarding the floodwater NH 4 -N concentration revealed that, the highest value of (NH 4M -N) was observed at the second day of PU application followed by gradual decrease with time. USG and NPK briquette treated plots showed negligible amounts of NH 4 -N in flood water during the sampling periods. The highest grain yield (5265 kg ha -1 ) and straw yield (6434 kg ha -1 ) was recorded from 104 kg N from USG (treatment T 3 ) and the lowest values were obtained from control. Apparent nitrogen recovery by rice plants was much higher when 78 kg N was applied as USG. Nitrogen use efficiency decreased with the increase in N rate either as PU, USG and NPK briquette and treatment T 7 (78 kg N as USG) showed the highest value. These results clearly indicate that the deep placement of N in the form of USG and NPK briquette minimizes the loss of N that results in higher N use efficiency and increased grain yield of rice as compared to broadcast application of N in the form of PU. DOI: http://dx.doi.org/10.3329/jesnr.v7i1.22173 J. Environ. Sci. & Natual Resources, 7(1): 207-213 2014