Transforming extension for sustainable agriculture: The case of integrated pest management in rice in Indonesia

Investment in agricultural extension, as well as its design and practice, are usually based on the assumption that agricultural science generates technology (“applied science“), which extension experts transfer to “users“. This model negates local knowledge and creativity, ignores farmers' self-confidence and social energy as important sources of change, and, in its most linear expression, does not pay attention to information from and about farmers as a condition for anticipating utilization. In practice, farmers rely on knowledge developed by farmers, reinvent ideas brought from outside and actively integrate them into complex farming decisions. Effective extension seems based on checks and balances that match intervention power with farmers' countervailing power, and mobilize farmers' creativity and participation in technology development and exchange. Alternative models for informing extension investment, design, and practice stress adult learning and its facilitation. The farmer is seen as an expert and farm development as driven by farmers' energy and communication. The article is a case study of a rare large scale attempt to use such an alternative model. It suggests that a shift to knowledgeintensive sustainable practices requires a learning process based on participation and empowerment.     

Proton nuclear magnetic resonance spectroscopy based investigation on propylene glycol toxicosis in a Holstein cow

Background

It is unknown which metabolites are responsible for propylene glycol (PG)-induced toxicosis, and a better understanding of the underlying mechanisms explaining incidences of abnormal behaviour of dairy cows fed PG is therefore needed.

Methods

The study included three cows of which one developed PG toxicosis. In order to investigate how the metabolism of PG differed in the cow developing toxicosis, proton nuclear magnetic resonance (NMR) spectroscopy was applied on ruminal fluids and blood plasma samples obtained before and after feeding with PG.

Results

PG toxicosis was characterized by dyspnea and ruminal atony upon intake of concentrate containing PG. The oxygen saturation of arterial blood haemoglobin and the oxygen pressure in arterial blood decreased along with the appearance of the clinical symptoms. NMR revealed differences in plasma and ruminal content of several metabolites between the cow responding abnormally to PG and the two control cows.

Conclusion

It is concluded that PG-toxicosis is likely caused by pulmonary vasoconstriction, but no unusual metabolites directly related to induction of this condition could be detected in the plasma or the ruminal fluid.     

Prediction of topsoil organic matter and clay content from measurements of spectral reflectance and electrical conductivity

Soil organic matter (SOM) and clay content of a soil characterized as a coarse sandy loam were modelled using hyperspectral reflectance data acquired with a spectrometer and soil electrical conductivity (SEC) data acquired with an EM38 instrument manufactured by Geonics Ltd. The partial least squares (PLS) regression method was applied and the results validated using cross validation. First, the models were calibrated using only spectral reflectance data; then EM38 data were included in the X-matrix of predictors. Although SEC is significantly correlated with clay content, the results showed that EM38 data did not improve model performance for the estimation of soil organic matter content and clay content, despite the fact that EM38 showed significant correlation with clay content.