Multi-location nutrient management studies on corn in Region 12 [Central Mindanao, Philippines]

The study aimed to calibrate soil test values of specific soil fertility constraints with corn yield responses to correction of the constraints and to promote the utilization of the different biofertilizer on corn. The sites selected were corn cluster areas in the provinces of Cotabato and Sultan Kudarat in Region 12 where corn was grown as the first and second crop. The upper 0-20cm layer of the soil had a pH from 5.1 to 6.6. The nitrogen (N) content was low (L), the phosphorus (P) content was low to medium (M) while potassium (K) was sufficient. The sites were homogenous within 0-3 percent slope or relatively flat. The soil textural class in Arakan, Cotabato was clay loam to heavy clay loam and in Bagumbayan, Sultan Kudarat was sandy loam. However, the treatments used were based on the initial trials and test values recommended from the UPLB Soil Fertility Laboratory of the different sites. The grain yield of corn (DK 9051) as influenced by the application of 6 fertilizer levels at Bagumbayan, Sultan Kudarat were observed in 2 farms and there was a significant difference among treatments wherein application of 130-30-30 kg N, P2O5, K2O/ha (T6) produced the highest yield both in farm 1 (6.76 t/ha). In farm 1, comparing treatment 5 (130-15-0) with treatment 4 (130-0-0) and treatment 1 (130-30-0), the grain yield of corn without application of K with the same levels of N and varies in P were comparable. Likewise, in farm 2 treatment 4 (130-0-0), treatment 3 (65-30-0) and treatment 1 (130-0-0) were comparable in grain yield without application of K and applied at different levels of N and P. These supported the initial findings that there was sufficient potassium in the soil. Similarly, the grain yield of yellow corn (DK 818) of farms 1 and 2 and white corn (P30W30) of farm 3 in Arakan, Cotabato observed a significant difference among treatments wherein application of 120-100-30 kg N, P2O5, K2O/ha (T6) produced the highest yield in farm 1 (6.95 t/ha), farm 2 (2.06 t/ha) and farm 3 (6.10 t/ha). This implies that application at different levels of fertilizer even in location with low average yield of less than 2.0 t/ha/cropping gave a higher yield of corn using both yellow and white corn. These findings on application of fertilizer on corn in specific-location would be more precise when soil and plants be subjected for laboratory analysis. Meanwhile, the performance of white hybrid (P30W30) revealed that increasing the fertilizer levels to 100 kg/ha had increase also in yield. On the other hand, application of 40-60 kg/ha inorganic fertilizer plus BI0-N and VITAL-N have shown a good result, it means that BI0-N and VITAL-N has a big role in the growth and yield performance of corn thereby, reducing the cost of applying commercial fertilizer per hectare. For yellow corn hybrid (DK 818), results indicated that as you increase the level of 100kg/ha, there is also an increase in yield. The yield increases from 5.78 t/ha to 7.27 t/ha when applied to 40 to 60 kg/ha inorganic fertilizer plus BIO-N and VITAL-N. Results showed a good performance in terms of corn yield, with biofertilizers like BIO-N and VITAL-N, you can minimize the use of commercial fertilizer, thus, reducing your production cost per hectare.