Soybean is one of major crops cultivated not only in Indonesia but also in other parts of world. It is significant source of nutrition for Indonesian people. Therefore, a special effort is needed to fulfill the national demand for soybeans, either by increasing crop productivity or expanding production sites. One of many alternatives to develop soybean cultivation in Indonesia is to optimize the use of marginal land. Tidal swamps are one of the potential marginal land ecosystems for future soybean production1.
The major constraint of soybean production in a tidal swamp is high pyrite content. This content suppressed the productivity of soybeans on tidal swamps. Soil water management can be applied to reduce pyrite content where the soil is in a reductive condition and able to support soybean growth.
Saturated soil culture (SSC) technology is method of soil water management that has been studied in the highlands and has succeeded in increasing soybean production. This technique has the ability to reduce pyrite and thus increase soybean yield in tidal swamps2.
The response of soybeans to saturated condition varies between cultivars. The later-maturing soybeans adapt better than the early-maturing varieties. The response of black soybean cultivars to SSC in tidal swamps has not been studied yet. Therefore, a new research was undertaken to study the effect of water depth and cultivar type on the nutrient uptake, growth and productivity of soybeans under SSC in tidal swamps3.
Nutrient uptake was indicated by the nutrient content in leaves of the soybean. Nitrogen, phosphorus, potassium and calcium content in soybean leaves cultivated with SSC were higher than those cultivated with dry culture. However, the difference in the water depth of SSC treatments did not result in differences in nutrient absorption.
It was also observed that the four soybean cultivars showed a different response to the watering system on the tidal swamp. This difference was expressed by genes in each cultivar in response to the environment, as plant growth is a gene-environment interaction (GXE) expression4.
Nutrient uptake influenced plant growth and plant growth influenced yield. The result showed the cultivars good at nutrient absorption expressed good growth and the highest yield. Avoidance of pyrite oxidation, availability of water and nutrients and high levels of solar radiation intensity supported good plant growth and yield under SSC on tidal swamps but did not occur in dry culture conditions.
The water depths and cultivars, as single factors, influenced the N, P, K and Ca nutrient uptake in soybeans. The water depth influenced the nodule, root, stalk and leaf dry weight, while the cultivar influenced the nodule and root dry weight.
This study will help researchers further to understand the best practices for overcoming pyrite oxidation in tidal swamps based on agronomic techniques that many researchers have not yet been able to explore. Further research may be needed on more efficient ways to apply SCC in tidal swamps.
Soybean, nutrient uptake, growth, yield, pyrite, saturated soil culture, tidal swamps, marginal land, overcoming pyrite oxidation, the nodule, root dry weight, culture conditions, Nutrient content, agronomy.
- Ghulamahdi, M., Chaerunisa, S. R., Lubis, I., & Taylor, P. (2016). Response of five soybean varieties under saturated soil culture and temporary flooding on tidal swamp. Procedia Environmental Sciences, 33, 87-93.
- Szögi, A. A., Hunt, P. G., & Humenik, F. J. (2000). Treatment of swine wastewater using a saturated-soil-culture soybean and flooded rice system. Transactions of the ASAE, 43(2), 327
- Ghulamahdi, M., Welly, H.D. and Sagala, D., 2018. Nutrient Uptake, Growth and Productivity of Soybean Cultivars at Two Water Depths Under Saturated Soil Culture in Tidal Swamps. J. Nutri., 17: 124-130.
- Sudaric, A., D. Simic and M. Vrataric, 2006. Characterization of genotype by environment interactions in soybean breeding programmes of Southeast Europe. Plant Breed., 125: 191-194.