Highly active biostimulant Paecilomyces variotii extracts reduced controlled‐release urea application while maintaining rice yield

Abstract

BACKGROUND The high cost of controlled‐release urea (CRU) has prompted this study to explore whether the amount of CRU can be reduced by adding biostimulants while maintaining or increasing rice yield. A 2 year field experiment was conducted with CRU at three levels (60%, 80%, and 100% of the recommended nitrogen (N) fertilizer) and a novel biostimulant Paecilomyces variotii extract (ZNC), to investigate their synergistic effects on yield, nitrogen use efficiency (NUE), and net profitability of rice. RESULTS Controlled‐release urea achieved a significantly higher gain yield and NUE than conventional urea with the same N level, which could be attributed to its N supply. Even if the N level of CRU was reduced by 40%, both rice yield and net profit were still significantly higher than for the full amount of urea. Paecilomyces variotii extract sprayed on the surface of CRU at a dose of only 87.5 mL ha−1 exhibited ultra‐high effectiveness by increasing the panicles, the N accumulation, and the rice yield. Controlled‐release urea enriched by ZNC achieved significantly higher gain yield than CRU alone, increasing the yield by 9.2% and 8.7%, respectively, in 2 years under the full recommended N rate. The combination of 80% CRU and ZNC showed no significant difference in rice yield from treatment with 100% CRU, indicating that the rate of CRU could be reduced by ZNC. The application of ZNC further increased NUE, N partial factor productivity, and net profit. CONCLUSION The CRU and ZNC combination provided a feasible approach for reducing N input while maintaining rice yield and agricultural sustainability. © 2021 Society of Chemical Industry.

Effect of Coated Diammonium Phosphate Combined with Paecilomyces variotii Extracts on Soil Available Nutrients, Photosynthesis-Related Enzyme Activities, Endogenous Hormones, and Maize Yield

“…However, the results of this study showed that ZNC combined with CDAP had a better yield-increasing effect in 2017 than the treatments CDAP or DAP combined with ZNC, increasing maize yield by 9.6 and 14.3%, respectively, and the yield difference was not significant in 2018. The ZNC contained a variety of carbohydrates, amino acids, and alkyl structures, and the recommended concentration ranged from 37.5 to 75.0 g ha –1 . , It was possible that the amount of ZNC used in this experiment, 3.08 mg kg –1 DAP, was not ideal and the effect was unstable due to the extremely low dosage, resulting in the combination of the two failing to show a synergistic yield increase in 2018. Additionally, there may be differences in objective environmental elements such as outdoor temperature and humidity, as well as weather conditions in the seasons of 2017 and 2018, resulting in differences in experimental results between the two years.…”

“… 17 Lu 18 found that higher concentrations of ZNC (100 ng L –1 ) could induce a plant immune response by activating the salicylic acid pathway, stimulating the accumulation of callosum in leaves, and improving the resistance of crops to pathogenic bacteria. Wang 19 also found that controlled-release urea enriched by ZNC achieved significantly higher gain yield than coated urea alone and further increased nitrogen (N) use efficiency, N partial factor productivity, and net profit. However, most of the previous studies on ZNC focused on laboratory simulation conditions, with few findings on the impact of ZNC application on the soil environment under natural growth conditions.…”