The Study On The Homeostasis And Growth Rate Of A Higher Plant And Their Mechanism

Amaranthus hypochondriacus L. were planted in sands and fertilized with different N and P level. The biomass, C%, N%, P% of leaves and stems, and which of roots, and N%, P% of soils were measured once a week (6 times totally). The relationship between the N%, P% and N:P of higher plants and the equivalency of soils and the relationship between the C%, N%, P%, N:C, P:C, N:P of plants and growth rate were studied. The results show: 1, The N%, P% and N:P of plants increase with the enhance of the soils'N%, P% and N:P, but the rate of increasement become smaller and smaller with the indexs go up. The relationship can be expressed by the equation y=a-bcx, which is significative to a certain extent because it can help to understand the mechanism of homeostasis. 2, The N and P of plants are coactivated. The P% of plants increase with the rise of N% of soils though the P% of soils are uniform. And the N% of plants inhance with the increase of P% of soils with the same N% of soils.But the effect of N to P is much more remarkable than the influence of P to N. 3, The relationship bitween N:C of plants and growth rate can be presented by the equation y=ax+b. That between P:C and growth rate can be denoted by y=ax2+b, N:P and growth rate by y=(ax+b)/(x2+c) when P is limited, and y=ax2+bx+c when N is limited. These equations can also be got by mathematical deduction depending on the mechanism of growth, so they can connect the infact and theory.