WHAT HAPPENS WHEN PLANTS DON'T GET ENOUGH NITROGEN: Plants deficient in nitrogen have thin, spindly stems and their growth is stunted. Their older leaves turn yellowish-green from nitrogen starvation (chlorosis), while newer leaves are supplied with the available, but limited nitrogen.
Although nitrogen enters the soil in several chemical forms, it eventually converts to the inorganic nitrate (NO3 – ) ion. Figure 1 shows that NO3 – can be used by plants, be converted back to nitrogen gas or be leached downward with soil water.
