A method for measuring the concentration of inorganic, monomeric Al in fluid samples was tested. The technique was found suitable as Al-organic acid complexes (malate) and polymeric Al (as calculated on the basis of sample pH and total Al concentration) did not interfere. A much simpler calibration procedure than in the original description by Kerven et al. (1989) was found satisfactory. Application of the technique to sample from a nutrient solution experiment show the importance of tight pH control in such experiments.
Tag: decay
Farmer-led community institutions: key to reversing land degradation in the 21st century
Reversing global land degradation is about better and simpler technologies, better national policies and much more. But ultimately it is about rural people and their institutions. The greatest prospect for reversing land degradation in the next century is the evolution of real farmer-led community institutions that take charge and transform the way research and extension in land management are done. Broad-based evidence for this is emerging. This paper will examine this as part of a process of people taking back greater control of their furures through decentralization, democracy and local leadership. Examples of locally-led processes in natural resource conservation suggest two successful streams: (1) institutions that are developed independently by local communities and managed by them, whose subsequent activities may not be assisted by outside stakeholders, and (2) local conservation institutions that are initiated and guided by the public sector.
Roots as sinks and sources of nutrients and carbon in agricultural systems
Roots are a special category of “soil biota” being part of organisms that live in two very different types of environment, aboveground and belowground. As they belong to the organisms that form the main target of all agricultural interventions and are directly involved in the efficiency with which nutrients and water are used for crop production, root knowledge should be “at the root” of any discussion on sustainable agriculture. Yet, little direct attention is given to roots, possibly because of a lack of (1) clear concepts on what to look for and (2) easy (be it quick and dirty) methods to observe the relevant properties in actual root systems.