Soil analysis can reduce expense and amount of fertilizer inputs in crop production

AGRICULTURE is one of the sectors that contribute to climate change aside. It contributes 14 % of the greenhouse gasses emitted in the atmosphere according to the intergovernmental panel on climate change (IPCC). Nitrous oxide for example accounts for 7 % warming effects. This nitrous oxide gas is emitted from the production and use of fertilizers and pesticides in agriculture.

To help mitigate the emission of the gas, farmers can practice soil management. One of the soil management practices is fertilizer application through soil analysis. Soil analysis can help reduce the expense and amount of fertilizer inputs in crop production. Through this method, the nutrient elements present in the soil are analysed as basis in fertilizer recommendation. In addition, the acidity of the soil can be known and the amount of lime to neutralize acidity can be determined.

In a technology transfer project made by the Climate Smart Agriculture (CSAC) of the Benguet State University through the World Food Program in Atok and Buguias, farmer co-operators applied fertilizers more or less than what the crop requires that led to higher fertilizer input expense.

In the project, plots planted with carrot using the BSU technology and plots using the farmers practice were prepared for comparison. Prior to planting, soil samples were collected for the analysis of soil pH, organic matter, nitrogen (N), available phosphorus (P) and exchangeable potassium (K) content of the soil. The soil analysis results were used in the determination of the amount of NPK and the kind of fertilizers to be applied in plots tagged BSU technology. On the other hand, the farmer co-operators applied their own practice in fertilizer application in the farmers practice plots.

Results of the techno transfer show that the farmer co-operator in Lengaoan, Bugias applied 300 g/6 m2 plot complete (14-14-14) while in the BSU plots, an amount of 260 g/plot in the form 14-14-14 and 240 g/plot urea in carrot indicating that the farmer applied less than what is required by the plant. In terms of expense, the farmer cooperator spent PhP 380.00 per plot (or about PhP 633,333.33/ha) while the BSU intervention spent PhP349.25 per plot (about PhP 582,083.33/ha). In Buyacaoan, the farmer spent PhP495.90 (about PhP 826,500.00) while the BSU intervention spent PhP 349.25 (about PhP 582,083.33/ha).

In another techno demo in barangay, Bashoy, kabayan, Benguet with cabbage as test crop, the farmer co-operator applied 0.7 kg/ 5m2 plot in the form of 8-8-8 fertilizer while in the BSU intervention plots, 0.26 kg/plot 14-14-14 and 0.12 kg/plot urea was applied indicating that the farmer applied less than what the cabbage require (24060-60 kg NP2O5K2O/ha). In terms of expense, the farmer spent PhP59.5/plot (or about PhP119,000.00/ha) compared PhP118,200.00/ha with the BSU intervention expense.

Results of soil analysis also showed that liming is recommended in the soils of the demo sites in Ekip, Bokod and Pacso, Kabayan with an identical soil pH value of 5.0. Application of 3 tons/ ha lime in the form of irisan lime (Hydrated lime) raised the soil pH to 6.1and 6.2, respectively. Increasing the soil pH is necessary since cauliflower requires a soil pH of 6.0-7.0

Interpretation of soil analysis however, will depend on the collection of soil samples. Thus, farmers were given demonstration on soil sampling. The farmers were also taught soil