Improved <strong>fallow</strong> <strong>systems</strong> <strong>in</strong> <strong>the</strong> Luang Prabang <strong>area</strong>, Lao PDR – an analysis based on farmer experiencesDiscussionImproved <strong>fallow</strong>?A good reason to believe that <strong>the</strong> <strong>in</strong>troduced <strong>fallow</strong> <strong>systems</strong> really <strong>improved</strong> <strong>the</strong> plotsperformanceis <strong>the</strong> farmers' op<strong>in</strong>ion that <strong>the</strong>y did. As mentioned earlier, it may be hazardous tofully trust such a statement, ma<strong>in</strong>ly because of a will to give a pleas<strong>in</strong>g, answer. This problemwas known dur<strong>in</strong>g <strong>the</strong> <strong>in</strong>terview<strong>in</strong>g work and steps were taken to avoid it: Questions wererepeated from different angles and problems were specifically asked for. The translator and <strong>the</strong>SCRP staff also had a good opportunity to decide if answers were genu<strong>in</strong>e. In <strong>the</strong>ir op<strong>in</strong>ion, <strong>the</strong>positive picture is what <strong>the</strong> farmers actually th<strong>in</strong>k.When try<strong>in</strong>g to f<strong>in</strong>d grounds for this op<strong>in</strong>ion <strong>in</strong> <strong>the</strong> collected data. years with "normal" conditionsshould be studied. The effect of "bad" years seems to over-shadow any positive effect of <strong>the</strong><strong>improved</strong> <strong>fallow</strong> <strong>systems</strong> (Figure 5). A problem when study<strong>in</strong>g <strong>the</strong> limited set of data is <strong>the</strong>statistical significance (Figure 12), and <strong>the</strong> result presented <strong>in</strong> Figure 6 should be seen as an<strong>in</strong>dication of an <strong>improved</strong> plot performance after <strong>improved</strong> <strong>fallow</strong>. The figure shows animprovement of about 20% after a 3 to 4-year <strong>fallow</strong> and a bit more after 5 to 10 years.Ano<strong>the</strong>r <strong>in</strong>dication of <strong>in</strong>creased plot performance could be <strong>the</strong> shorter <strong>fallow</strong> cycles after<strong>in</strong>troduction of <strong>improved</strong> <strong>fallow</strong> species (Figure 8). The villages <strong>in</strong> <strong>the</strong> SCRP <strong>area</strong> show such apattern, while <strong>the</strong> FAO/IJNDP villages show <strong>in</strong>creas<strong>in</strong>g <strong>fallow</strong> cycle times. This can probably beexpla<strong>in</strong>ed by <strong>the</strong>ir access to markets <strong>in</strong> Luang Prabang, which give <strong>the</strong>m <strong>the</strong> opportunity of us<strong>in</strong>go<strong>the</strong>r crops than rice. disturb<strong>in</strong>g <strong>the</strong> crop rotation pattern.The data on crop cuts (Figure 7) show an expected pattern but shares <strong>the</strong> problem of statisticaluncerta<strong>in</strong>ty). Of <strong>the</strong> two sections with <strong>improved</strong> <strong>fallow</strong> (b & c), <strong>the</strong> b-section, with <strong>the</strong> longer <strong>fallow</strong>period also has a higher yield than <strong>the</strong> c-section. Compared with <strong>the</strong> plot section newly openedfrom forest, both <strong>improved</strong> <strong>fallow</strong> sections have a higher yield. This could mean that on this plotan <strong>improved</strong> 3-year <strong>fallow</strong> is as good as a newly opened section, but also that <strong>the</strong> data haserrors. As <strong>the</strong> mean yield data are so similar and have overlapp<strong>in</strong>g confidence <strong>in</strong>tervals (Figure13), <strong>the</strong> variation between <strong>the</strong> three sections probably has little importance. It was also unclearwhat <strong>the</strong> farmer thought about differences between <strong>the</strong> sections.In Figure 9 an attempt is made to compare <strong>the</strong> <strong>improved</strong> <strong>fallow</strong>- plots with<strong>in</strong> <strong>the</strong> MI. & <strong>area</strong> witho<strong>the</strong>r plots <strong>in</strong> <strong>the</strong> same <strong>area</strong>. For normal years, yields after different lengths of <strong>fallow</strong> are almostidentical with <strong>the</strong> <strong>area</strong> averages for 1999 (a "good" year). As mean yield figures of <strong>the</strong> <strong>improved</strong><strong>fallow</strong> <strong>area</strong>s are compared with a wet„ "good" year, it can be seen as an improvement. A ma<strong>in</strong>problem with this comparison is that many different SCRP plots yields for two years (1998 and1999) are compared with data on <strong>improved</strong> <strong>fallow</strong> plots from o<strong>the</strong>r years. Also, <strong>the</strong> comparison ismade between different plots, while a relationship <strong>in</strong> Figure 6 is based on data for <strong>the</strong> same set ofplots. Ano<strong>the</strong>r complication is that farmer estimates are compared with crop cuts.When consider<strong>in</strong>g <strong>the</strong> shown effects of a "bad" year, a quite unpredictable yield variation. <strong>the</strong>comparison between <strong>improved</strong> and un<strong>improved</strong> plots for <strong>the</strong>se years seems even moreuncerta<strong>in</strong>.With <strong>the</strong> available data it is hard to give a dist<strong>in</strong>ct picture of an enhancement of <strong>the</strong> plots'productivity after <strong>improved</strong> <strong>fallow</strong>. For <strong>the</strong> time be<strong>in</strong>g, <strong>the</strong> farmers' op<strong>in</strong>ions are <strong>the</strong> ma<strong>in</strong> reasonto believe that <strong>the</strong> plantation of Leucaena and Pigeon pea may be of benefit to yields.Preferred speciesTo get an idea about how different comb<strong>in</strong>ations of <strong>improved</strong> <strong>fallow</strong> species perform, yield datafor different <strong>fallow</strong> species comb<strong>in</strong>ations were p4lotted aga<strong>in</strong>st years of <strong>improved</strong> <strong>fallow</strong> Figure 10<strong>in</strong>dicates that <strong>the</strong> comb<strong>in</strong>ations where Leucaena are present give higher yields than comb<strong>in</strong>ationswithout Leucaena. The grasses offer extra weed<strong>in</strong>g work and are quite competitive, which mayhave an effect on yields.IMPROVED FALLOW SYSTEMS IN THE LUANG PRABANG AREA, LAO PDR - AN ANALYSIS BASED ON FARMEREXPERIENCES.20040940 13
Improved <strong>fallow</strong> <strong>systems</strong> <strong>in</strong> <strong>the</strong> Luang Prabang <strong>area</strong>, Lao PDR – an analysis based on farmer experiencesDiscussionFrom this <strong>in</strong>formation Leucaena appears to be <strong>the</strong> best choice of species. This is also supportedby its survival abilities. Leucaena survive by far <strong>the</strong> highest number of cropp<strong>in</strong>g cycles, be<strong>in</strong>g stillpresent at almost all plots (Figure 11).IMPROVED FALLOW SYSTEMS IN THE LUANG PRABANG AREA, LAO PDR - AN ANALYSIS BASED ON FARMEREXPERIENCES.20040940 14
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