Study of Land Quality and Land Characteristics that Determine the Productivity of Composite Maize Varietiesin Gorontalo
Nurdin, M. L Rayes, Soemarno, Sudarto.
The challenge of composite maize developing in the future is the low productivity because the maize is grown on land that is not suitable for land quality. This study aims to determine the land quality and land characteristics that control the composite maize productivity in Gorontalo Province. A total of 33 land units were surveyed and their land observed to obtain data on morphology and soil characteristics, climate and terrain characteristics, as well as composite maize productivity data through ubinan plots and direct
interviews with maize farmers. Partial least square of structural equation models (PLS-SEM) analysis has been used to determine the land quality and land characteristics that control the composite maize productivity through variable validity and reliability tests, as well as structural model tests. The results showed that the manifest variables were air temperature, rainfall, wet months, dry months, LGP, drainage, coarse materials, effective depth, pH H2O, pH KCl, C-organic, total N, available P, available K, ESP, slopes, soil erosion, inundation height, inundation time, surface rock, and rock outcrops were valid and able to explain well the latent variables. Furthermore, the latent variables were temperature, water availability, oxygen availability, nutrient retention, nutrients availability, sodicity, erosion hazard, flood hazard, and land preparation used has good composite reliability and high reliability because of the composite reliability and alpha cronbach >0.6. Land quality that controls the composite maize productivity based on the order of importance were nutrient retention, rooting media, land preparation, and nutrients availability. Meanwhile, land characteristics that control the composite maize productivity based on the order of importance were pH KCI, coarse material, rock outcrops, effective depth, surface rock, available K, and soil texture. Soil texture, effective depth, pH KCI, and available K has a positive relationship and has a significant to very significant effect on the composite maize productivity, while the content of course materials, surface rock, and rock outcrops has a negative relationship and has a significant effect on the composite maize productivity.