Why Can't We Use Sea Water for Farming? Sea water is very salty. Salt have high impact on altering the pH value of soil. When pH value is altered, plant can’t absorb the nutrients from soil and the nutrients will react with the salt and convert into non plant usage forms.
There are some important reasons to it. Have a look at the following:
1. Adaptation Plants that are regularly accustomed to being irrigated by fresh water are not likely to survive the salt water concentration. This is because salt water is a hypertonic solution as compared to fresh water. The plant cells when irrigated by salt water will leave water from their cells into the surrounding water to maintain the osmotic balance to reduce salt concentration. This will cause the plants to eventually wilt away.
2. Accumulation If the land is continuously irrigated with salt water, eventually there will be a mass buildup of salts in the land causing the land to lose its fertility. The soil will become saline and will continue to be so till rain water or any other fresh water washes away the excess salt. Only limited plants can grow on saline soil, including mangroves and coconut and salt water weeds as they have gradually adapted to saline environment and this process takes a considerably long time.