Fertilizers applications

The best overall recovery of labelled fertilizer in crop and soil was 99% and the leastsatisfactory 65%. Thus 1-35% ofthe labelled nitrogen, onaverage 15.7%, was missing, presumed lost . These losses occurred between the time of the fertilizer application in spring and the time the crop was harvested but why and how did they occur ... 

Figure 5 A surplus nitrate curve , relating the amount of nitrate left in the soil at harvest to that given in spring as fertilizer. The point at which the curve turns upwards represents the safe limit for fertilizer application. It could be described as the environmental optimum application. Fortunately, it is often close to the economic optimum.

A recent review of research on phosphorus input to surface waters from agriculture highlights the variability of particulate and dissolved phosphorus contributions to catchments. The input varies with rainfall, fertilizer application rates, the history of the application of the fertilizer, land use, soil type, and between surface and sub-surface water. The balance struck between export of nutrients from the catchment and recipient-water productivity is the primary factor which controls its quality. 

Figure 8 The effect of fertilizer application and rainfall and the emissions of NO and N,0 from clay loam soils cropped with ryegrass cut for silage in South Scotland.

Proceedings of the First International Congress on Phosphorus Compounds and their Non-fertilizer Applications, 17-21 October 1977 Rabat, Morocco, IMPHOS (Institut Mondial du Phosphat), Rabat, 1978, 767 pp. 

An agricuiturai chemist wished to study the effect of varying fertilizer applications on the growth of tomato piants. The chemist prepared a stock aqueous solution of urea, (NH2)2 CO, by dissolving 1.75 g of this compound in water to make 1.00 L of solution. Then she prepared a series of more dilute solutions to apply to her tomato plants. One of these solutions contained 5.00 mL of stock solution diluted to give a final volume of 25.00 mL. What was the concentration of urea in this diluted solution ... 

Maintenance activities During the first 18 months, irrigation was conducted to help establish the vegetation. Once or twice a year, brush is cleared to comply with Fire Department regulations. Prior to the rainy season, an inspection is conducted to check and clear debris basins and deck inlets. No mowing activities or fertilizer applications have been conducted or are planned. 

Stamatiadis S, Werner M, Buchanan M (1999) Field assessment of soil quality as affected by compost and fertilizer application in a broccoli field (San Benito County, California). Appl Soil Ecol 12 217-225... 

Hammer K, Knupffer H, Laghetti G, Perrino P (1992) Seeds from the past. A catalogue of crop germplasm in South Italy and Sicily. Germplasm Institute of CNR, Bari, Italy Henson RA, Bliss FA (1991) Effects of N fertilizer application timing on common bean production. Fertil Res 29 133-138... 

Fertilizer application rates of, 77 124-126 techniques for, 77 124 Fertilizer coating, ionomers as, 74 483 Fertilizer industry growth of, 23 789... 

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