Today, I’d like to present my field research I conducted in Madagascar in these two years. The title is A study on SRI in the central highland of Madagascar, and as a subtitle, I put rice yields, rice cultivation management and high yielding factors of SRI farms. So let me start now.
Je d'abord montre les elements du SRI. Je pense que vous les connaissez bien, mais j'explique un peu. Premiere element, ca c'est~ 2em element,~ 3em element, on utilise beaucoup de fumier comme compost. 4em element,~ , donc on fait irrigation pas toujours, mais on fais la terre repetivement mouille et seche, mouille seche pendants la croissance vegetative.Ca vous dire on doit controler de l'eau bien. 5em~
Et sur cette SRI qui etait developpe ici au Madagascar, il y a beaucoup de discussion dans le monde. Quelques supporteurs disent que~ ou bien,~ Ils disent que cette SRI sera une solution de la stagnation du productivite du riz dans le monde. Pendants a peu pres ces dix ans, le rendement du riz dans le monde augmente pas presque rien, et la production du riz par tete maintenant diminue a meme niveau que cella des annees 1980s. Mais, il y a aussi beaucoup de scientist , surtout IRRI sont negatif sur SRI.. Ils disent que c'est pas vrais. C'est faux!
Comme les scientists quis sont negatif sur SRI disent, il'y a quelques questions on doit repondre. ce sont ~, et ~.
We conducted 3 experiments below, in the central highland of Madagascar, mainly in the region of Fianarantsoa. We selected 4 SRI and 4 conventional fields, and during the harvest season in 2005, we measured the rough grain yields at each paddy field, and interviewed farmers on their rice cultivation management. For the second experiment, we conducted on-farm experiments at 3 SRI fields, S1, S2 and S3, where we did a field survey, and 2 conventional fields, C1 and C2, which are adjacent to the SRI fields of S1 and S2. For the third experiment, we analyzed the soil chemical properties of all the survey and experimental fields taken from the depth of 0-15cm and 15-30cm.
In the result of the field survey,
We compared the rice yields and rice-cultivation management practices at each SRI and conventional field. The yield measurement at Ambatofutsi was not conducted because of the heavy damage from blast disease. When we look at the yields at the other fields, two of the SRI fields obtained almost 10 t/ha of rice yields, and the yield at the SRI fields were over twice as great as conventional yield on average. Either improved or local varieties were cultivated in both of SRI and conventional fields. As for the transplanting methods, relatively young seedlings were transplanted with wide spacing at SRI fields. Cow dung or compost was applied at all the SRI fields, and two of the conventional fields. At the SRI fields, SRI-water management, which is intermittent irrigation during the vegetative growth stage fallowed by shallow flooding, or shallow flooding through the whole growth period was conducted. These fields had good irrigation and drainage system. Weed control was more frequently done in the SRI fields. And in all the SRI fields, deep plowing was practiced
Here are the photos of management practices which were observed in the SRI fields.Sparse transplanting of young seedlings, compost application, deep plowing, and building a drainage system.
Here’s the picture of SRI field at maturity on the left, and a conventional field on the right.
As a result of field survey, we found a close similarity of rice-cultivation management practices between SRI farmers in this study and the winners of rice-yield contest held in Japan, back in 1950s and 60s. Organic amendments and intermittent irrigation, which are key techniques of SRI, and deep plowing and drainage, which were observed in the survey fields were also conducted by yield-contest winners in Japan.
We conducted on-farm experiments on the effect of SRI techniques in the season of 2005-2006.
We selected 3 SRI fields, S1, S2 and S3, and 2 conventional fields, C1 and C2. As for the treatments, we designed 2 different seedling-age practices, young seedlings and middle-aged seedlings, and two different transplanting patterns, sparse transplanting and dense transplanting at all the 5 fields. In addition to these two treatments, the plot with compost and the plot without any fertilization were made at S2, and the plot with SRI-water management and the plot with continuous flooding were made at S3. Weed control was frequently done at all the fields. All the treatments were replicated twice.
This is a photo of one experimental field. SRI-water management was conducted on the left, and the right plot was continuously flooded. On the upper side of the field, young seedling was transplanted in a transplanting density of 16 hills m-2 and 26.7 hills m-2. On the lower side, middle-aged seedlings were transplanted likewise.
First, we look at the yield of each fields, and there was large yield difference among the experimental fields from 2.4 t/ha at C1 and 9.0t/ha at S3. The result of ANOVA test for the effect of each treatment on rice yields are also shown in this table. SRI-water management and compost application increased rice yields by 17 %, and by 12 %, respectively, although these treatments were only made at one field. The effect of seedling age was not significant at the 4 fields, but transplanting young seedlings increased the yields by 8 % at S2. Sparse transplanting had no effects on yields at S1, S2 and S3, where yields were relatively high, but it decreased yields at C1 and C2 by 25 %, where yields were relatively low.
We conducted further analysis how SRI water-management increased rice yield, in respects of soil redox potential and plant nitrogen uptake, but it’s too in detail, so let me skip this.
I skip this, too.
This table shows the amount of organic matter, mineralizable nitrogen, available phosphorus and cation exchange capacity in the soil of all the study fields. When we look at the organic matter content, the SRI fields have relatively great organic matter compared to conventional fields. When we further look at this organic matter for upper soil layer and deep soil layer separately, the amounts decreased at the deep soil layer in the conventional fields, but the value was maintained at the SRI fields. This indicates that large amount of organic matter from upper to deep soil layer exist at the SRI fields. The amount of mineralizable nitrogen was also doubled in SRI fields on average. We found several conventional fields which had very low amount of available phosphorus or low CEC, but these values were high in all the SRI fields.
This research was done only for very small number of fields, and SRI techniques were not fully evaluated at all. but clarifying high-yielding factors of the fields where farmers obtain very high yields with no chemical fertilizer might be an useful approach to improve and sustain yields of resource-limited fields, as Japan increased its national yield average partly by learning the techniques of rice-yield contest winners in 1950s and 60s.
0756 SRI au Madagascar: Rendement, Méthodes Riziculture, et des Facteurs de Meilleur Rendement dans les Rizières de SRI
SRI au Madagascar Rendement, méthodes riziculture, et des facteurs de meilleur rendement dans les rizières de SRI Yasuhiro Tsujimoto Graduate School of Agriculture Kyoto University
Eléments du SRI <ul><li>Repiquage du jeunes plants , 8-12 jours après le ensemencement . </li></ul><ul><li>Repiquage spacieux (16 pieds/m 2 ) </li></ul><ul><li>Emploi de la mati è re organi que abondant e. </li></ul><ul><li>Irrigation intermittente pendant la croissance végétative, et après irrigation peu profond jusqu’à maturité. </li></ul><ul><li>Le sarclage fr équent. </li></ul>Techniques intensives, origine au Madagascar dans 1980s
Controverses sur SRI <ul><li>On peux doubler ou tripler le rendement avec SRI sans extra ressource </li></ul><ul><li>Rapports de rendements plus que 15 t/ha </li></ul><ul><li>= Système de riziculture qui améliora le productivité dans les régions sans ressources. </li></ul><ul><li>Touts les rapport sur SRI manquent les renseignements détaillés et les données scientifiques </li></ul><ul><li>Rapports de super-high yields sont probablement a cause de erreur de mesure </li></ul>
Objectifs <ul><li>Est-ce qu’il y a des paysans qui réalisent du rendement plus que 15 t/ha? </li></ul><ul><li>Facteurs des meilleurs rendements dans ces riziers? </li></ul>
Materials and Methods 0 100 km 200 SRI field Antananarivo Fianarantsoa km 0 Fianarantsoa to Antananarivo 15 30 Main road Maromby Mahazengy Ambalavao Tolongoina Ambalamerina Soatanana Ambatofutsi Conventional field Main city 1. A field survey Rendements et méthodes cultures dans les rizières SRI et conventionnelles 2. On-farm experiments Effets de chaque technique de SRI 3. Soil analysis Caractéristiques de la terre dans les rizières SRI et conventionnelles 14°S 16° 18° 20° 22° 24° 46° 44°E 48° 50° S1 S2 S3 C1 C2
Rendement du riz au chaque traitement 17 % 12 % 8 % 26% 24%
Soil redox potential and plant N uptake between different water management More oxidative soil condition Maintenance of root activity at the later growth stage Larger N uptake from PI to maturity Shallow flooding
Insufficient compensation for the reduced panicles at the low-yielding fields
Conclusion de on-farm experiments <ul><li>L’effets des techniques SRI sur rendement </li></ul><ul><li>SRI-W; 17 % , Compost; 12 % </li></ul><ul><li>Ketsa 8 andro; 0~ 8 % </li></ul><ul><li>Repiquage spacieux; 0~ -25 % </li></ul><ul><li>Rendements sont augmente a un certain degre, </li></ul><ul><li>(mais) pas double ou triple que lequel conventionnel </li></ul><ul><li>Propriétés de la terre? </li></ul>
Conclusion <ul><li>Rendement et méthodes riziculture aux champs du SRI </li></ul><ul><li>1. 9.9 t/ha au maximum, plus de double que conventionnel </li></ul><ul><li>2. Techniques du SRI, plus drainage et labour profond </li></ul><ul><li>Facteurs des meilleurs rendements dans ces rizières </li></ul><ul><li>1. La terre fertile, surtout azote minéral abondant </li></ul><ul><li>2. L’effets des techniques SRI </li></ul>
Champs du SRI dans cette étude Japon Records du concours au Japon Madagascar Changement du rendement du riz au Japon et Madagascar, et records du concours au Japon (FAOSTAT, 2004) Rendement (t/ha) Année
Y (rendement) = f ( Xc, Xs, X t, Xw ) Xc; Méthode riziculture ( Variété, Date de repiquage, fertilisation, contra saison ) Xs; Propriétés de la terre ( SOC, Azote, Phosphore, CEC ) Xt; Topographie de la rizière ( altitude, accessibilité de irrigation) Xw; Conditions climatiques ( Température, Radiation du soleil ) Y am (rendement) = f ( Xc am , Xs am , X t, Xw ) Expérience des variétés, des dates de repiquage Evaluation de la matières organiques Remote sensing Recherche de la végétation locale Interview Analyse de la terre