Page 168 - Ilmu Tanah Book

The Chemistry and Fertility of Soils under Tropical Weeds 155

Chapter 9.

Closing Remarks

9.1 The Chemistry of Soils under Weed Management
9.2 The Availabilities of Plant Nutrients under Weed Management
9.3 The Use of Effective Weeds
Key Questions

W
eeds are very unique vegetation. In addition to the fact that they are
very expansive and competitive, the also significantly affect the soil
environment. Weeds are reported to significantly affect the soil
chemical, soil biochemical, and the soil physical properties. Therefore, weeds may
affect the soil fertility and the growth of crop plants.
+
Weeds roots excrete H and organic acids that provide two of the very
+
important chemical species in the soil environment i.e. H ions and organic
complexing agents. Hydrogen ions may eventually lower the soil pH. The evolution
of CO 2 from hydrocarbon oxidation in weed roots and microorganism associated
with weed roots may intensify the soil ambient acidification due to the formation
Abdul Kadir Salam and Nanik Sriyani – 2019