Application of controlled release urea improved grain yield and nitrogen use efficiency: A meta-analysis

Area of Science:

• Agricultural Science
• Soil Science
• Agronomy

Background:

• Conventional urea (CU) application poses environmental risks.
• Controlled release urea (CRU) is a potential alternative to mitigate these effects.
• Data on CRU's impact on major staple crops (wheat, maize, rice) is limited.

Purpose of the Study:

• To quantitatively assess CRU's effects on soil properties, nitrogen uptake, grain yield, and nitrogen use efficiency (NUE) in staple crops.
• To compare CRU with CU in terms of crop production and environmental impact.
• To identify conditions under which CRU is most beneficial.

Main Methods:

• A meta-analysis was conducted using data from studies in China.
• Soil chemical properties (SOC, TN, AN, pH) were analyzed.
• Crop yield, total nitrogen (TN) uptake, and various nitrogen use efficiency metrics (NUE, NAE, NUR, NPE) were evaluated.

Main Results:

• CRU significantly increased soil organic carbon (SOC), total nitrogen (TN), and available nitrogen (AN).
• CRU application resulted in a 7.23% increase in grain yield and a 9.13% increase in TN uptake compared to CU.
• CRU significantly enhanced NUE, nitrogen agronomy efficiency (NAE), nitrogen utilization rate (NUR), and nitrogen physiological efficiency (NPE).

Conclusions:

• CRU application improves soil fertility and enhances staple crop production and nitrogen utilization.
• The benefits of CRU on yield and NUE are most pronounced in soils with low SOC and TN.
• Promoting CRU, especially for infertile soils, is recommended for sustainable grain production.