Swan(sea) Song – personal research during my six years at Swansea ... and bey...
0401 Why and How this Century's Agriculture Should be Different from 20th Century Agriculture
1. Why and How This Century’s Agriculture Should Be Different from 20th Century Agriculture National Seminar on Resource Management and Sustainable Development College of Agriculture Bapatla, AP, January 28, 2004 Norman Uphoff Cornell International Institute for Food, Agriculture and Development (CIIFAD)
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3. Per Capita Food Production, 1961-2000, and Agricultural Commodity Prices, 1960-2000
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9. Changes in Fertilizer Productivity World Grain Production Fertilizer Response Use Ratio 1950 631 14 - 1984 1649 126 9.1:1 1989 1685 146 1.8:1 1993 1719 130 Not calculable
27. Two rice plants in Cuba -- Same variety: 2084 (Bollito) Same age: 52 DAP
28. SRI field in Sri Lanka -- yield of 13 t/ha with panicles having 400+ grains
29. Two rice fields in Sri Lanka -- same variety, same irrigation system, and same drought : conventional methods (left), SRI (right)
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33. Root Activity in SRI and Conventionally-Grown Rice Nanjing Agricultural University (Wang et al. 2002) Wuxianggeng-9 variety
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Editor's Notes
This picture was contributed from Cambodia by Koma Yang Saing (CEDAC). Viewers should try to imagine the very small single young seedling from which this massive plant grew.
Picture provided by Gamini Batuwitage, Sri Lanka, of field that yielded 17 t/ha in 2000.
This picture from Sri Lanka shows two fields having the same soil, climate and irrigation access, during a drought period. On the left, the rice grown with conventional practices, with continuous flooding from the time of transplanting, has a shallower root system that cannot withstand water stress. On the right, SRI rice receiving less water during its growth has deeper rooting, and thus it can continue to thrive during the drought. Farmers in Sri Lanka are coming to accept SRI in part because it reduces their risk of crop failure during drought.
These data from a study done by Fide Raobelison under the supervision of Prof. Robert Randriamiharisoa at Beforona station in Madagascar, and reported in Prof. Robert's paper in the Sanya conference proceedings, give the first direct evidence to support our thinking about the contribution of soil microbes to the super-yields achieved with SRI methods. The bacterium Azospirillum was studied as an "indicator species" presumably reflecting overall levels of microbial populations and activity in and around the plant roots. Somewhat surprisingly, there was no significant difference in Azospirillum populations in the rhizosphere. But there were huge differences in the counts of Azospirillum in the roots themselves according to soil types (clay vs. loam) and cultivation practices (traditional vs. SRI) and nutrient amendments (none vs. NPK vs. compost). NPK amendments with SRI produce very good results, a yield on clay soil five times higher than traditional methods with no amendments. But compost used with SRI gives a six times higher yield. The NPK increases Azospirillum (and other) populations, but most/much of the N that produced a 9 t/ha yield is coming from inorganic sources compared to the higher 10.5 t/ha yield with compost that depends entirely on organic N. On poorer soil, SRI methods do not have much effect, but when enriched with compost, even this poor soil can give a huge increase in production, attributable to the largest of the increases in microbial activity in the roots. At least, this is how we interpret these findings. Similar research should be repeated many times, with different soils, varieties and climates. We consider these findings significant because they mirror results we have seen in other carefully measured SRI results such as the Anjomakely factorial trials (Slide 24) and the previous season's trials with SRI at Beforona (10.2 t/ha).