Can crop roots absorb fertilizer? Methods to improve fertilizer uptake efficiency

Crops absorb fertilizer nutrients through their roots mainly relying on their extensive root system. For example, the root system of a mature rice plant has 200-300 roots, with some having 600-700, and each root has many branch roots, with root hairs at the tips of the branch roots, which serve to expand the root system's absorption area for water and nutrients. From the seedling stage onward, the root system has the ability to absorb water and nutrients. To make crops absorb more nutrients, the root system should be encouraged to grow well; otherwise, no matter how rich the soil nutrients are, they cannot be “eaten” up.

In production, people adopt measures such as plowing the soil, cultivating and loosening the soil, applying more fertilizer, and rational drainage and irrigation precisely to help crops form an extensive root system and robust plants, so that the crops can “eat their fill, drink enough, and live comfortably,” thereby achieving the goal of more flowering, more fruiting, and higher yields.

Appendix: Which fertilizers cannot be used for foliar topdressing?

Foliar topdressing has the advantages of quick results and fertilizer savings, and is widely adopted by farmers. However, after fertilization, results are also slow; in sandy soil and soil with low organic matter content, quick-acting fertilizers such as ammonium sulfate, urea, and potassium chloride that are applied are easily lost with rainwater and irrigation water. Although they have good fertilizer supply properties, they have no lasting effect, resulting in “small seedlings growing, old seedlings not growing,” and crop yields are also relatively low. Therefore, soils with different fertilizer retention and supply capacities should be treated differently in fertilization. For sandy soil with poor fertilizer retention capacity and soil with low organic fertilizer content, in addition to applying more organic fertilizer in the base fertilizer, chemical fertilizers should be applied “in small amounts multiple times” to avoid “burning seedlings” and nutrient loss caused by excessive single application, and to prevent premature aging caused by fertilizer shortage in the later stage; for clayey soil with better fertilizer retention performance, or soil with more organic matter, because of good fertilizer retention, a larger single application of chemical fertilizer will not cause “seedling burn” or nutrient loss, but this kind of soil “grows old seedlings, not small seedlings,” so in the early stage of crop growth, seed fertilizer or early topdressing should be applied to promote early growth, and in the middle and late stages of growth, nitrogen fertilizer application should be controlled to avoid excessive vegetative growth or rampant growth of crops, which can cause yield reduction.