| authors: | He, Z. ; Alva, A. ; Calvert, D. ; Li, Y. ; Banks, D. |
| title: | Effects of Nitrogen Fertilization of Grapefruit Trees on Soil Acidification and Nutrient Availability in a Riviera fine sand |
| year: | 1999 |
| source: | Plant & Soil 206: 11-19 |
| URL: | Please log in to access the document. |
| abstract: | Nitrogen (N) fertilizer applied in the NH4 form results in some degree of soil acidification, which could influence nutrient availability to plants and nutrient losses through leaching. Effects of various N rates (0 - 168 kg N ha?1yr?1) on soil acidification and nutrient availability were investigated in a Riviera fine sand with 26-year-old white Marsh grapefruit (Citrus paradise MacFadyen) trees. Soil pH significantly decreased with increasing NH4-N rates. Application of 112 kg N ha?1yr?1 for four years decreased the pH by 0.7 to 1.7 units. Soil acidification was greater when the Nh4 form of N fertilizer was applied as dry granular material compared to fertigation or controlled release forms. The marked effect of NH4-N fertilization on the pH of the Riviera fine sand was due to its low buffering capacity. Soil acidification increased the concentration of extractable FE and P but increased that of K, Zn and Mn. Soil pH was positively correlated with concentration |
| keywords: | Acidification, grapefruit, nitrogen fertilizer, nutrient availability, leaching, sandy soil, sustainability. |
