Abstract
An ideal and efficient nitrogen (N) recommendation for precision fertilization (PF) should account for potential soil mineralizable N. This study aimed at estimating management zone (MZ) specific soil N mineralization rate (SNMR) of unamended soils. A total of 76 soil samples were collected from 21 MZs across 5 fields. An aerobic laboratory incubation was conducted under controlled conditions for two months with seven sub-sampling events. N mineralization was assessed as net increase in soil mineral N over time. Results indicated a considerable variation in mineralized soil N (9.12–41.93 mg kg−1 soil) across fields. Highest and lowest net SNMRs were 0.50 and 0.0004 mg kg−1 soil day−1, respectively. SNMRs significantly differed across MZs in three fields, while in the other two fields no significant differences were observed. In turn, 3 of 34 MZ-pairs differed (marginally) significantly (padj = 0.02–0.09) from one another, namely in MZ pairs with high variation in soil particle sizes. MZ-specific SNMRs were mostly positively correlated to pH (0.20–1.00), total N (0.12–0.99), soil mineral N (0.11–1.00) and sand (0.34–0.99), negatively correlated with clay (− 1.00 to − 0.11) and correlations with SOC were mixed (0.41 to − 0.62). This along with the support from regression analysis corroborated the existing knowledge that TN is a better predictor of mineralization than SOC. While there were only few statistically significant differences in SNMR amongst MZ per field despite mathematical differences, still incorporating MZ-specific SNMR in management decisions will be crucial in optimizing the N use efficiency in precision farming, and along with other management actions, lead to more environmentally friendly PF schemes.
Original language | English |
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Pages (from-to) | 1906-1931 |
Number of pages | 26 |
Journal | Precision Agriculture |
Volume | 24 |
Issue number | 5 |
DOIs | |
Publication status | Published - Oct 2023 |
Externally published | Yes |
Keywords
- Laboratory incubation
- Management zone
- Precision fertilization
- Soil nitrogen mineralization
- Soil spatial variabilities
- Soil–water environment