The value of calcium nitrate and urea for sugar beet, and the effect of late nitrogenous top dressings

Abstract

1. Twenty-eight experiments on sugar beet in 1956–8 compared ammonium sulphate, calcium nitrate and urea applied to the seedbed before sowing. The three fertilizers were compared at rates which supplied nil, 0·6 and 1·2 cwt. N/acre. Treatments in which 0·6 cwt. N/acre was held back until the end of June were also included.2. Average responses in sugar yield were low, 0·6 cwt. N/acre provided virtually all the nitrogen required for maximum sugar production. The heavier nitrogen dressing, on the other hand, substantially increased the yield of tops.3. Calcium nitrate and urea were as effective as ammonium sulphate at raising sugar yield. There was no damage to germination with any fertilizer, and when urea containing 4·5% biuret was used for topdressing in 1956, no damage was seen. Calcium nitrate and, to a lesser extent, urea produced more tops than ammonium sulphate.4. Putting all the nitrogen into the seedbed was as effective as a split dressing in raising sugar yield. Leaching of nitrogen in a wet summer is therefore not important to sugar beet. Late nitrogen, on the other hand, never harmed sugar production if some had been given to the seedbed.

Nitrate nitrogen in leaves and petioles of sugar beet in relation to yield of sugar and juice purity

“…To use leaf analyses for advice on manuring of the crop, they must be made available in time for late applications of nitrogen to be given. Adams (1960) showed that nitrogen can be applied until late in June with little loss in sugar yield, but still later applications decrease both sugar percentage and total yield. Plants must therefore be analysed in early June, at the 4-to 8-leaf stage; analyses might be used to decide the dressings in subsequent years, but differences between seasons and cultivations diminish the chances of success, especially because there is a statutory interval of 3 years between beet crops on a field.…”

“…2). Split dressings produced smaller concentrations early in the season and larger ones later, and such dressings may diminish sugar percentage (Adams, 1960).…”

Field experiments on the value of urea as a fertilizer for barley, sugar beet, potatoes, winter wheat and grassland in Great Britain

“…Widdowson, Penny & Cooke (1960) found that urea containing < 1 % biuret and ammonium sulphate gave similar yields of potatoes at rates up to 168 lb./acre of nitrogen, with no check to early growth, but that urea containing 4-5 % biuret checked early growth and gave lower yields than ammonium sulphate, especially at high rates of application. For sugar beet, Adams (1960) found that urea gave similar sugar yield's but slightly higher yields of tops than ammonium sulphate. Templeman (1961) reported that urea gave rather smaller increases in dry matter yield of grass than those from 'Nitro-chalk', while both sources gave similar average yields of wheat.…”

Effect of Time and Rate of Application of Nitrogen and Date of Harvest on the Yield and Sucrose Content of Sugar Beets1

“…Rate of nitrogen application = Date of harvest > > Time of nitrogen application > Interactions. 1 Authorized for publication by the Director as Journal Article No. 3620 of the Michigan Agr.…”

“…Generally, beets have responded best to early applications of nitrogen fertilizers (5, ;2, 10). However, Adams (1) found that the sugar yield 1 was not reduced when nitrogen was applied late if some nad been applied as a preplant or at planting time. Haddock (9) noted no difference in root yield due to sidedre~sing nitrogen in midseason as compared to sidedressing iri early season.…”