When the Universal Soil Loss Equation was first introduced in lab last week, we discussed how South America and Africa finally had their own soil maps. The significance of this is that these two continents have had problems with producing their own crops since problems like desertification and erosion are present. With these new soil maps, it will become easier to know where to plant and farmer will have a better idea on what will grow best where. The soils in some of the regions of South America and Africa are for the most part different than some of the soils that are farmed in more developed regions. For this reason, there cannot be one uniform application of farming for every land in every ecosystem and with every soil type. I met someone a couple years ago who traveled to Madagascar with the World Wildlife Fund to teach farmers to use better farming practices on their soils. As with many underdeveloped lands, slash and burn was the predominant method in Madagascar and vast amounts of nutrients and topsoil was being lost.
Last July, Science Daily published an article on the conservation farming practices that have been developed for tropical soils. In areas with rainforest such as the Amazon, the biomass is mostly above ground, leaving little nutrients and organic matter in the soil. So, when slash and burn clearing happens, there is not a sustainable method for farming. This study, on the same premise as the study conducted at University of Illinois, is long term. For 19 years, cover crops, crop rotation, and tillage on soil organic carbon storage were studied in Brazil. According to the Journal of Agronomy, “no tillage management combined with crop rotations including winter cover crops with high amounts of crop residues returned annually to the soil will most likely maintain soil organic carbon stocks and most likely mimic natural forested condition for tropical and subtropical areas.” Another article in Science Daily discussed farmers in Zimbabwe and what can be done to increase crop yeilds there as well. While chemical fertilizer and manure are not very common, just using a small bit can help substantially. Low levels of nitrogen added to the arid soil was able to increase maize yields between 50%-100%. One method that is commonly practiced in areas other than Zimbabwe is crop rotation with nitrogen fixing legumes.
At this time, developing countries are for the most part dependent upon developed countries for their food sources. By devising efficient methods for harvest, this may not longer be the case. Many conservation methods are in practice in more developed countries, but these methods cannot be applied across the board. World hunger is a problem that has been addressed by many humanitarian groups, and possibly one of the best solutions is to provide better methods for developing countries to produce their own food, not for it to be sold to them.
If you’d like to see the articles,