For example, in the case of soils deficient in both nitrogen and sulphur, application of nitrogen only may actually cause a reduction in yield as a result of nutrient imbalances within the plant. Excessive quantities of nitrogen, under some conditions, prolong the growing period and delay crop maturity. This effect can be partly overcome by applying sufficient phosphorus and potassium. Lodging Lodging usually is caused by a combination of excess nitrogen fertilizer or available nitrogen in the soil and excess soil moisture. The extra vegetative growth resulting from nitrogen application can lead to lodging in unfavorable weather.
Heavy lodging reduces the flow of nutrients and moisture to the pods and seeds of the plant.
Excessive nitrogen application should be avoided on fertile soils. However, weather conditions can also cause lodging with the present varieties and may reduce crop response to high nitrogen rates. It is important that growers make a realistic estimate of the yield potential of the crop when choosing fertilizer rates. Soil moisture reserves, soil moisture holding capacity and annual growing season precipitation must be considered when estimating yields and choosing fertilizer application rates. The potential yield increase from applying nitrogen is directly related to the stored soil moisture and growing season precipitation.