Fertilization, growth response

The increased growth response documented in almost all the solarization studies is mainly due to the above-cited higher levels of macronutrients or the improved uptake of micronutrients solubilized by humic substances (Chen and Aviad 1990 Chen et al. 1991). As a consequence of the enhancing effect of solarization on soil nutrients, Flores et al. (2007) suggested the application of low rates of mineral fertilizers before heating soil, in order to avoid an increased vegetative growth of the plants at the expense of crop yield. 

These results indicate that host plant resistance in cotton will remain a fertile ground for future research. The association of volatile terpenes with glands, and the hormetic and antibiotic effects of one member of this group, are persuasive arguments for bioassaying other compounds. The unexpected synergistic effects observed when G and CO are fed as a mixture demand further study. Thus we intend to expand these studies to more fully define the contours of this growth-response surface, and extend this research to other terpenes. 

Jonasson, S. (1992). Growth responses to fertilization and species removal in tundra related to community structure and clonality. Oikos 63,420-429. 

Second, the model does not predict the growth response to fertilization above levels required to compensate for nutrients removed in the harvested material. The parameters for wood and leaf growth are currently put into the nutrient balance model from the growth model as independent parameters. Growth is only indirectly related to the nutrient balance through the use of land class productivity data in the growth model for the prediction of biomass production. Any fertilization necessary to raise the fertility of the site to a level required to sustain a desired amount of productivity would be included in the transition period costs. The necessary detailed data required to estimate optimum fertilizer schemes are not presently available. 

Essentiality. Evidence for the nutritional essentiality of vanadium is not conclusive. Strasia (37) found that rats fed less than 100 ng of vanadium/g of diet exhibited slower growth, higher plasma and bone iron, and higher hematocrits than controls fed 0.5 Mg of vanadium/g of diet. However, Williams (38) was unable to duplicate the findings of Strasia (37), even in the same laboratory under similar conditions. Schwarz and Milne (39) reported that a vanadium supplement of 25 to 50 Mg/100 g of a semi-purified diet gave a positive growth response in rats. On the other hand, Hopkins and Mohr (40) reported that the only effect of vanadium deprivation on rats was an apparent impaired reproductive performcince (decreased fertility and increased perinatal mortality) that became apparent only in the fourth generation. 

Brockley, R.P. 1989. Response of thinned, immature lodgepole to nitrogen fertilization Three-year growth response. FRDA Report 036, British Columbia Ministry of Forests, Victoria, B.C. 37 pp. 

Increased levels of nitrogen and phosphorous reduced the Inhibition of barley (Hordeum vulgare L.) growth caused by -coumaric and vanillic acids (8a). Although other explanations are possible, these effects of fertilizers suggest that Inhibition of mineral absorption was responsible for the observed Inhibition of growth. 

---