But not to sound too negative - other farming methods can be pretty good production-wise as well. Its just that we would need to use and develop them too instead of relying on the harmful methods currently widely in use. And these alternative methods do not fit in with the corporate agriculture model as well - nor do they fit for making farmers dependent on agribusiness products (from fertilizers, pesticides to genetically modified terminator seeds)
Like: (I pasted the first page almost entirely, second page at link)
http://allafrica.com/stories/200902270229.html
A key question that is often asked about ecological agriculture, including organic agriculture, is whether it can be productive enough to meet the world's food needs. While many agree that ecological agriculture is desirable from an environmental and social point of view, there remain fears that ecological and organic agriculture produce low yields.
This short paper will summarise some of the available evidence to demystify the productivity debate and demonstrate that ecological agriculture is indeed productive.
In general, yields from ecological agriculture can be broadly comparable to conventional yields in developed countries. In developing countries, ecological agriculture practices can greatly increase productivity, particularly if the existing system is low-input, which is the largely the case for Africa. This paper will focus mainly on evidence from developing countries.
EVIDENCE FROM GLOBAL MODELLING
A recent study examined a global dataset of 293 examples and estimated the average yield ratio (organic:non-organic) of different food categories for the developed and developing world (Badgley et al. 2007). For most of the food categories examined, those conducted the study found that the average yield ratio was slightly less than 1.0 for studies in the developed world, but more than 1.0 for studies in developing countries.
On average, in developed countries, organic systems produce 92 per cent of the yield produced by conventional agriculture. In developing countries, however, organic systems produce 80 per cent more than conventional farms.
With these average yield ratios, the researchers then modelled the global food supply that could be grown organically on the current agricultural land base. They found that organic methods could hypothetically produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without putting more farmland into production.
Moreover, contrary to fears that there are insufficient quantities of organically acceptable fertilisers, the data suggest that leguminous cover crops could fix enough nitrogen to replace the amount of synthetic fertiliser currently in use.
This model suggests that organic agriculture could potentially provide enough food globally, but without the negative environmental impacts of conventional agriculture.
EVIDENCE FROM REVIEWS OF ECOLOGICAL AGRICULTURE PROJECTS
In a review of 286 projects in 57 countries, farmers were found to have increased agricultural productivity by an average of 79 per cent, by adopting 'resource-conserving' or ecological agriculture (Pretty et al. 2006).
A variety of resource conserving technologies and practices were used, including integrated pest management, integrated nutrient management, conservation tillage, agro-forestry, water harvesting in dryland areas, and livestock and aquaculture integration into farming systems. These practices not only increased yields, but also reduced adverse effects on the environment and contributed to important environmental goods and services (e.g., climate change mitigation), as evidenced by increased water use efficiency and carbon sequestration, and reduced pesticide use.
The work built on earlier research, which assessed 208 sustainable agriculture projects. The earlier research found that for 89 projects for which there was reliable yield data, farmers had, by adopting sustainable agriculture practices, achieved substantial increases in per hectare food production - the yield increases were 50 to 100 per cent for rain-fed crops, though considerably greater in a number of cases, and 5 to 10 per cent for irrigated crops (Pretty and Hine 2001).
Disaggregated data show:
- The average food production per household rose by 1.7 tonnes per year (up by 73 per cent) for 4.42 million small farmers growing cereals and roots on 3.6 million hectares.
- The increase in food production was 17 tonnes per year (up 150 per cent) for 146,000 farmers on 542,000 hectares cultivating roots (potato, sweet potato, cassava).
- Total production rose by 150 tonnes per household (up by 46 per cent) for the larger farms in Latin America (average size 90 hectares).
The database on agricultural sustainability (comprising the 286 projects) was re-analysed to produce a summary of the impacts of organic and near-organic projects on agricultural productivity in Africa (Hine and Pretty 2008). The average crop yield increase was even higher for these projects than the global average (79 per cent), representing a 116 per cent increase for all African projects and a 128 per cent increase for projects in East Africa.
For Kenyan projects, the increase in yield was 179 per cent, for Tanzanian projects 67 per cent, and for Ugandan projects 54 per cent. Moreover, all case studies that focused on food production in this research where data have been reported showed increases in per hectare productivity of food crops, which challenges the popular myth that organic agriculture cannot increase agricultural productivity.
EVIDENCE FROM SPECIFIC ECOLOGICAL AGRICULTURE INTERVENTIONS
Data from the Tigray Project in the Tigray Region in Ethiopia, where a project on ecological agriculture has been carried out since 1996, concretely demonstrate the benefits of compost on productivity. Preliminary data collected in 1998 had already shown that using compost gave similar yield increases as chemical fertilisers. Data collected in 2002, 2003 and 2004 showed that, on average, composted fields gave higher yields, sometimes double, than those treated with chemical fertilisers (Araya and Edwards 2006).
In a new paper written for the UN Food and Agriculture Organization (FAO), statistical analysis on a larger data set over the years 2000 to 2006 inclusive confirms that compost use in Tigray has increased yields in all the crops analysed (Edwards et al. 2008). In total, data was collected from 974 fields from 19 communities. Grain and straw yield data were obtained for barley, durum wheat, finger millet, hanfets (a mixture of barley and durum wheat), maize, sorghum, teff, faba bean and field pea.
Except for field pea, the compost generally doubled the grain yield when compared to each respective check (crops grown without any inputs). (For field pea, the increase in yield was approximately 28 per cent). The difference was significant (95 per cent confidence limit). The application of compost also increased straw yield compared to the check, but not to the same extent as it increased grain yield.
The use of compost also gave higher yields than the use of chemical fertiliser, though differences in the yields from compost and from chemical fertiliser were not as great as the differences between the use of compost and the check. For sorghum and faba bean the yields from the use of compost and chemical fertiliser were similar. But the yield difference for all the other crops was greater, with that from the compost treatment always higher than that from the use of chemical fertiliser. The results also showed that compost not only increases the overall biomass yield, but also increases the proportion of the grain to straw in the yield.
Since 1998, the Bureau of Agriculture and Rural Development of Tigray Region has adopted the making of compost as part of its extension package, and by 2007 at least 25 per cent of the region's farmers were making and using compost. A reflection of the success of this approach is that between 2003 and 2006, grain yield for the region almost doubled from 714 to 1,354 thousand tonnes. Since 1998, there has also been a steady decrease in the use of chemical fertiliser, from 13.7 to 8.2 thousand tonnes.
There are many other specific examples of increased yields following the application of ecological agricultural practices, some of which are summarised below (Hine and Pretty 2008; Parrott and Marsden 2002; Pretty and Hine 2001; Scialabba and Hattam 2002).
