Phosphorus Balance and Soil Phosphorus Status in Paddy Rice Fields with Various Fertilizer Practices
| Autor: | Toshiyuki Nagumo, Shintaro Tajima, Sanae Chikushi, Ayako Yamashita |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Plant Production Science, Vol 16, Iss 1, Pp 69-76 (2013) |
| Druh dokumentu: | article |
| ISSN: | 1343-943X 1349-1008 |
| DOI: | 10.1626/pps.16.69 |
| Popis: | Excess phosphorus (P) has accumulated in Japanese paddy soils, due to fertilizer P inputs over crop requirement for several decades, and improvement of the excess of P is necessary in view of environmental conservation. This study aimed to evaluate the input/output balance of P related to soil P status in paddy rice systems, and to obtain a practical indication. Irrigated rice (Oryza sative L.) was cultivated on a gley soil from 1997 to 2006. Six field plots fertilized with commercial fertilizer, animal waste composts, green manure and none were included. Phosphorus input varied among plots from 0 to 73 kg ha-1 yr-1. Rice P uptake was approximately 20 kg ha-1, indicating no response to the P input. This was attributed to a large amount of plant-available Bray- and Truog-P in our soils. In our fields, paddy rice could be cultivated with no P-containing fertilizer or amendment. As a result, increase in the P input led to an increase in partial P balance (PPB). Cumulative increase in PPB resulted in the increase in soil total P, whereas cumulative decrease of PPB tended to decrease it. Excess accumulation of the soil P results in a loss of P into the environment. We concluded that P fertilization should be restricted to 20 kg ha-1 yr-1 (corresponding to 46 kg ha-1 yr-1 as P2O5), based on evenly balanced P input with the rice P uptake. It is also important to include all of the P-containing fertilizers and amendments when determining the amount of application. |
| Databáze: | Directory of Open Access Journals |
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