Improving Farming Practices for Sustainable Soil Use in the Humid Tropics and Rainforest Ecosystem Health

Abstract

Abstract:Unsustainable farming practices such as shifting cultivation and slash-and-burn agriculture in the humid tropics threaten the preservation of the rainforest and the health of the local and global environment. In weathered soils prone to cohesion in humid tropic due to low Fe and carbon content and the enormous amounts of P that can be adsorbed, sustainable soil use is heavily dependent on the availability and efficient use of nutrients. This paper reviews the literature in the field and provides some insights about sustainable soil use in the humid tropics, mainly for the Brazilian Amazonia region. Careful management of organic matter and physical and chemical indicators is necessary to enhance root growth and nutrient uptake. To improve the rootability of the arable layer, a combination of gypsum with continuous mulching to increase the labile organic matter fraction responsible for the formation of a short-lived structure important for root growth is recommended, rather than tillage. Unlike mulching, mechanical disturbance via ploughing of Amazonian soils causes very rapid and permanent soil organic matter losses and often results in permanent recompaction and land degradation or anthropic savannization; thus, it should be avoided. Unlike in other regions, like southeast Brazil, saturating the soil solely with inorganic potassium and nitrogen soluble fertilizers is not recommended. Nutrient retention in the root zone can be enhanced if nutrients are added in a slow-release form and if biologically mediated processes are used for nutrient release, as occurs in green manure. Therefore, an alternative that favors using local resources to increase the supply of nutrients and offset processes that impair the efficiency of nutrient use must be pursued.

Efficiency of Wheat Straw Biochar in Combination with Compost and Biogas Slurry for Enhancing Nutritional Status and Productivity of Soil and Plant

“…An increase in plant N content and maize growth by biochar application [56,57] may be due to the higher surface area of biochar that retains NH 4+ in the soil and its high CEC [58]. It was observed by many studies that the combined application of biochar and other organic treatments increases nutrients availability and moisture retention that ultimately improves plant growth and soil quality [8,34,59].…”

“…Eutrophication has been caused by nutrients leaching into the water bodies [6,7]. Similarly, extensive farming practices have reduced soil organic matter (SOM) contents thereby increasing cation exchange capacity (CEC) of soils and lowering fertilizer use efficiency [8]. Maintaining an optimum level of nutrients through management practices and organic amendments play a significant role in sustainable crop production and improving soil fertility [9].…”

Untitled

“…Enriching compost before introducing to soil with Azotobacter inoculant become a very simple method to introduce N fixing bacteria. In tropics, the soil usually contains low amount of N because of high precipitation and daily temperature [7] and farmers anticipate the low avilability N during plant growth by introducing significant amount of N fertilizer, mainly urea. By using N fixing biofertilizer, the level of N fertilizer will be reduced and hence protect the soil health.…”

Particleboard Manufactured from Rubberwood RRIM 2002 Clone Planted with Different Fertilizer Treatment

“…Besides the breeds factor, soil nutrients also play roles in tree growth and timber properties. Most tropical soils are highly weathered, and levels of P, Ca, Mg, Zn, S, N, K, Cu, and B are low or very low [8]. For tree growth, N, P and K play a vital a role and it is very crucial to ensure these nutrients have enough amount to be consume by the trees.…”