Search



Show Advanced search options Hide Advanced search options
Effects of a band application of polyolefin-coated diammonium phosphate on the nutritional quality of rhubarb and Swiss chard
Published August 23, 2000
39-42.

Dietary intake of large amounts of nitrates and oxalates presents a health hazard. In this study experiments were conducted with two oxalate accumulating vegetables rhubarb (Rheum rhabarbarum L.) and Swiss chard (Beta vulgaris L. var. cicla L.)) using POC-DAP in order to improve their nutritional quality. In the rhubarb experi...ment oxalate content was significantly reduced by band application of POC-DAP, while effects on ascorbate and nitrate contents were ambiguous. The improved nutritional quality in the POC-DAP treatment was rather a cause of ammonium nutrition than a cause of less amount of released fertilizer nitrogen. In the Swiss chard experiment oxalate and nitrate contents were reduced, while ascorbate content was increased by a band application of POC-DAP. The improved nutritional quality in the POC-DAP treatment was the cause of both the less amount of released nitrogen and the realised ammonium nutrition. It was also found that by using POC-DAP for Swiss chard cultivation, labour and energy costs of top-dressings could be eliminated without yield decrease. It was concluded that the nutritional quality of rhubarb and Swiss chard could be improved by using a band application of POC­DAP.

 

Show full abstract
631
146
Reducing nitrate content in lettuce using polyolefin-coated fertilizers
Published August 23, 2000
35-38.

Pot experiments were conducted in order to investigate the effects of the controlled-release characteristic, nitrogen form and application method of polyolefin-coated fertilizers on the nitrate content and yield of lettuce (Lactuca sativa L.). Comparing broadcast application of polyolefin-coated urea (POCU) and urea at four fertilizati...on levels, it was found that application of POCU decreased the nitrate content and increased the yield, due solely to its controlled-release characteristic. Comparing band applications of POCU or polyolefin-coated diammonium-phosphate (POC-DAP) to broadcast application of ammonium nitrate, it was found that a band application of both urea and ammonium containing polyolefin-coated fertilizers can decrease nitrate content in lettuce, without causing any significant yield decrease. This was a combined effect of the controlled-release characteristic and realized ammonium nutrition. Comparing effects of broadcast, band and spot applications of POC-DAP, it was found that nitrate content, was the lowest in the spot application treatment. However, considering both nitrate content and yield, band application was found to be the most effective application method.

 

Show full abstract
96
143
1 - 2 of 2 items