Sulfur nanoparticle coated urea improves growth and nitrogen use efficiency in wheat (Triticum aestivum L.) and rice (Oryza sativa L.)

Ahmad Fraz^1,2Asma Imran^1*Hammad Raza²Muhammad Iqbal²Asma Rehman¹

• ¹National Institute for Biotechnology and Genetic Engineering (Pakistan), Faisalabad, Pakistan
• ²Government College University, Faisalabad, Faisalabad, Punjab, Pakistan

Nitrogen (N) is an essential macronutrient required for plant productivity. Urea is a major source of N in global agriculture systems which is mostly lost due to leaching, runoff and volatilization, inflicting serious productivity, economic and environmental issues. On contrary, coated urea minimizes N losses by decreasing urease activity and enhances its efficiency by maintaining a continuous N-supply for plant uptake and productivity. Present study describes the impact of S NPcoated urea (S NP CU) on the morpho-physiological, biochemical, and yield traits of rice and wheat.Chemically synthesized S NP coated onto urea revealed a fine layer of S NP on urea under Scanning electron microscope. Two varieties each of rice and wheat grown in pots were fertilized as follows:Control N/recommended non-coated urea U100, three doses of S NP CU (50%, 70%, and 90% of recommended N) all in split dose . Analysis revealed that S NP CU at all doses increased the growth and yield parameters of both crops. Maximum increase was observed in S NP CU90 i.e., chlorophyll (up to 39%), carotenoids and proteins (up to 20%), sugars and amino acids (up to 60%), along with an increase of at least 5% or above in agronomic efficiency, 10% or above in grain weight, 6% or above in harvest index and 70% or above in N-uptake in both cultivars of wheat and rice. S NP CU90 increased the nitrogen recovery efficiency by 34 and 26% in wheat varieties Galaxy and FSD-2008 while 36 and 30% in rice varieties Green super and 1121 basmati, respectively. S NP CU90 decreased urease activity up to 37%, 52% at day 2 while 16% and 25% at day 15 in wheat and rice, respectively. This delay increased the duration of N availability in soil for wheat and rice plants, resulting increased NUE till 15 days. This study has demonstrated that S NP CU minimizes N loss, revealing that even lower application of S NP CU fulfill the crop N demand. It is concluded that S NP CU at lower rates can be used for large scale testing in fields for reducing N-losses and improving yields.