Potassium Plus Biopolymer Coating Controls Nitrogen Dynamics of Urea in Soil and Increases Wheat Production

Abstract

The low nitrogen utilization efficiency (NUE) of commercial fertilizers is one of the main hurdles in higher crop production and reduction of fertilizer N losses to the environment. However, interactions between most the macronutrients could have synergistic outcomes that affect crop NUE. The coating of urea with macronutrients and biopolymers may control N release and synergistically impact its crop NUE. In this study, urea was coated with 3% of different polymers, combined with 5% potassium iodide (KI) (i) Gum Arabica (GA + KI), (ii) polyvinyl alcohol (PVA + KI), and (iii) gelatin (Gelatin + KI) to control its N release, leaching, and increase of wheat NUE. Scanning electron microscopy, Fourier Transform Infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses confirmed the successful coating of all KI and biopolymer combinations on urea granules. All coating combinations slowed down urea release in water and reduced its leaching from the soil, but the highest reduction in both parameters was observed with the GA + KI treatment, compared to the uncoated urea. After soil application, GA + KI decreased urea leaching by 26% than the uncoated urea in lysimeter. In the field, soil mineral N remained significantly high with the GA + KI and PVA + KI treatments at the wheat tillering, booting, grain filling and maturity stages, compared to the uncoated urea. However, K content was only high (28%) with the GA + KI treatment at final harvest. Likewise, microbial biomass N was only high with GA + KI at grain filling (20%) and maturity stages (24%) than the uncoated urea. Such synchronized N availability led to high wheat grain yield (28%), N (56%) uptake, and apparent N recovery (130%) with the GA + KI treatment, compared to the uncoated fertilizer. The increment in NUE with GA + KI could be due to the synergistic effect of K on N availability; therefore, we observed higher wheat yield and N utilization efficiency with this treatment. Hence, urea coated with macronutrient (K) plus biopolymer is recommended to improve wheat yield, NUE, and for reduction of environmental N losses.

Effect of slow-release nitrogenous fertilizers on dry matter accumulation, grain nutritional quality, water productivity and wheat yield under an arid environment

“…Enhanced efficiency of fertilizers with 50% of total N applied at the booting stage had highly significant association with grain quality that proved split application benefits for chemical qualities of wheat 40 . The findings of previous research also showed that polymer coated controlled release urea increased soil N, P and K availability and such synergistic effects led to higher grain yield, N uptake and its recovery (%) in clay loam soils Nezami et al 41 and proved strong support for the current research findings.…”

“…Our results showed that BSCU and SCU showed more crop index % than uncoated and neem coated urea. This might be due to slow release fertilizers balanced the nutrients in soil and more availability in plants rhizosphere 2 , 37 , 41 . The S has acidic properties and neutralized the soil's alkalinity 2 .…”

Effect of chitosan iodate complex biofortification on nutrient uptake in ‘shivam’ hybrid of tomato (Solanum lycopersicum L.)

“…It was observed in the present study the highest potassium uptake was recorded in combined Cs-KIO 3 and FA-KIO 3 treatments (T 9 , T 10 , T 13 and T 14 ) in both crops' plants and fruits (Table 1 and 2). The increased uptake of K in the crop might result from the increased availability of K in the soil due to the application of potassium iodate, which contains 18% K (Nezami et al, 2021). Two foliar sprays of KIO 3 along with SA -KIO 3 or Cs-KIO 3 complex increased the potassium uptake compared to the treatments that received one foliar spray.…”

“…14 ) enhanced the uptake of nitrogen (61.23 and 78.43 Kg ha -1 ), phosphorous (9.88 and 16.79 Kg ha -1 ), potassium (86.45 and 135.89 Kg ha -1 ),…”

Bioactive Zincated Urea Effectively Enhanced Crop Yield, Nitrogen Use Efficiency, and Grain Quality in Maize and Rice

“…The earlier studies reported 50% N losses as NH 3 volatilization [13], 30% as NO 3 leaching/ runoff [14] and >30% as denitrification [15]. The crop plants utilize only 30-60% of applied-N as urea [14,16] and hence N use efficiency (NUE) of crops varies accordingly [14,16,17]. The low NUE could lead to economic losses to farmers as well as environmental hazard.…”