One-time fertilization of controlled-release urea with compound fertilizer and rapeseed cake maintains rice grain yield and improves nitrogen use efficiency under reduced nitrogen conditions

Abstract

Nitrogen (N) rate reduction and simplified fertilization can mitigate environmental impacts and reduce the involvement of manual labor in rice (Oryza sativa L.) production. Controlled-release urea (CRU) has been recommended as an effective alternative technique to conventional urea fertilization, and it can improve rice yield and N use efficiency (NUE) and reduce labor costs. However, the information on the effects of one-time fertilization with CRU on maintaining yield and improving NUE under reduced chemical N conditions is limited. In this study, controlled-release bulk blending fertilizer (CRF), consisting of CRU with release periods of 40 and 100 days, mixed with compound fertilizer, was applied as basal fertilizer. Increased ~20% plant density (ID) and rapeseed cake fertilizer (RC, increase 20% organic N) were combined with CRF, respectively. The N treatments with 20% chemical N reduction were as follows: reduced N fertilizer (RNF), CRF, CRF+ID, and CRF+RC. In addition, a conventional split fertilizer application with 300 kg ha-1 N was applied as the control (CK). Rice yield and its components, dry matter accumulation, N uptake, and NUE were investigated to evaluate whether one-time N fertilization realized stable yield and high NUE under reduced 20% chemical N conditions. Compared with CK, the CRF+RC treatment exhibited a comparable grain yield, while the other reduced N treatments (RNF, CRF, and CRF+ID) had a lower grain yield. Moreover, CRF+ID exhibited a higher rice grain yield than RNF or CRF under the same N level. Irrespective of exogenous organic N, CRF+RC exhibited significantly higher NUE than CK. The CRF+ID treatment showed a significantly higher N partial factor productivity (PFN) than CK but comparable N agronomic efficiency (NAE) and N recovery efficiency (NRE). Therefore, a one-time fertilizer application of CRF+RC maintained grain yield and improved the NUE while reducing the N rate and fertilization times, demonstrating its potential application in rice production.

Exploring the Effects of Nitrogen Fertilization Management and Soil Factors on the Yield and Quality of Flue-Cured Tobacco in China—A Quantitative Research

“…This may be due to the fact that better synchronization between high plant N demand and sufficient N availability in the soil at appropriate growth stages accounts for the higher yield response under split applications [41]. Interestingly, one-time root zone fertilization has also been demonstrated to successfully enhance the increase in the production of cotton and rice [42,43]. This suggests that precise nitrogen management in the root zone could provide a higher intensity of nitrogen supply, promoting efficient nutrient absorption by crops [44].…”

Urea-Loaded Core–Shell MOF/Silica Nanocarriers for Continuous Nitrogen Release to Crops

“…Chemical fertilizers as important nutrients determine plant growth and crop yield, which further affects the food supplies. Currently, excessive and inappropriate use of chemical fertilizers has caused severe economic and environmental problems, including resource waste and water pollution. , The controlled release fertilizer (CRF) method enables the sufficient use of nutrients from fertilizers, avoiding nutrient loss resulting from volatilization and leaching, achieving labor-saving one-time fertilization. − However, the CRF method often faces difficulty for practical large-scale application due to the following reasons: first, the current reported commercial CRFs are usually economically costly and show an unsatisfied release efficiency for crop cultivation; , second, the reported CRF materials are mainly petroleum-based polymers synthesized by a redundant process and often introduce toxic substances into the fertilizers. − Petroleum-based polymers are difficult in biodegradation and circulation, resulting in environmental and energy problems, − while the biodegradable materials including starch, lignin, cellulose, and chitosan indicate serious weakness in mechanical strength. − Besides, biodegradable materials usually result in fast nutrient release often due to abundance in hydrophilic groups, impeding their practical and large-scale application . Therefore, development of an environmentally friendly fertilizer delivery method based on advanced materials is highly desired.…”