In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining...In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.展开更多
Planting date is a critical component of soybean [Glycine max （L.） Merr.] production, under dry land conditions in the Southeastern Coastal Plain. The objectives of this study were to 1. Evaluate the effect of plant...Planting date is a critical component of soybean [Glycine max （L.） Merr.] production, under dry land conditions in the Southeastern Coastal Plain. The objectives of this study were to 1. Evaluate the effect of planting date on plant leaf area index （LAI） and normalized difference vegetation index （NDVI） at 60 and 90 days after planting （DAP）, plant height and grain yield, and 2. Determine the optimum planting period by integrating the responses from vegetation growth to yield for soybean maturity group （MG） IV-VIII under dry land conditions in the Southeastern Coastal Plain. Planting dates were scheduled about 14-days intervals from late April to mid-July （2008） or late July （2009）. Greatest grain yield for MG IV was obtained from planting in around mid-May in both years. The yield was greater for MG V planted in May and greater for MG VI-VIII planted in late April and May, but started to decline for planting in early June. Plant LAI and NDVI at 60 DAP were affected by both planting date and precipitation, but were poorly correlated with grain yield. However, plant LAI and NDVI were well correlated with yield and were greater for May planting dates at 90 DAP. These indiccs declined for soybean planted after May. Mature plant height decreased more rapidly with delayed planting. These results indicate that plant growth and yield decreased after May planting. Optimum planting period for all MGs was early to mid-May.展开更多
基金the Korea Forest Service for funding this research(Project No.S211316L020130)
文摘In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.
文摘Planting date is a critical component of soybean [Glycine max （L.） Merr.] production, under dry land conditions in the Southeastern Coastal Plain. The objectives of this study were to 1. Evaluate the effect of planting date on plant leaf area index （LAI） and normalized difference vegetation index （NDVI） at 60 and 90 days after planting （DAP）, plant height and grain yield, and 2. Determine the optimum planting period by integrating the responses from vegetation growth to yield for soybean maturity group （MG） IV-VIII under dry land conditions in the Southeastern Coastal Plain. Planting dates were scheduled about 14-days intervals from late April to mid-July （2008） or late July （2009）. Greatest grain yield for MG IV was obtained from planting in around mid-May in both years. The yield was greater for MG V planted in May and greater for MG VI-VIII planted in late April and May, but started to decline for planting in early June. Plant LAI and NDVI at 60 DAP were affected by both planting date and precipitation, but were poorly correlated with grain yield. However, plant LAI and NDVI were well correlated with yield and were greater for May planting dates at 90 DAP. These indiccs declined for soybean planted after May. Mature plant height decreased more rapidly with delayed planting. These results indicate that plant growth and yield decreased after May planting. Optimum planting period for all MGs was early to mid-May.
