Experiment Study For Sodic Soil Reclamation With By-product From Flue Gas Desulphurization In The Field

The use of gypsum to reclaim sodic soil has last more than 100 years in the world. However, because of its higher cost, it is not popularized until now. The way of using by-product from flue gas desulphurization to reclaim sodic soil is put forward in recent years, and the related theory for it is not perfect. The text objective is to research the change rule of soil physics and chemistry characters, plant growth and yield under the condition of using different amount of by-product from flue gas desulphurization, finding out the optimum utilization pattern of by-product from flue gas desulphurization, and provide theory guarantee and technical guide for large-scale application. Eight different experiment treatments were devised, two factors—sodic soil category and the amount of by-product from flue gas desulphurization, four levels—different amount of by-product from flue gas desulphurization; in strongly sodic soil, the amount of by-product from flue gas desulphurization is 3.75t/hm~2,7.5 t/hm~2, 11.25 t/hm~2 and 15 t/hm~2; in sodic soil, the amount of by-product from flue gas desulphurization is 18.75 t/hm~2,22.5 t/hm~2,26.25 t/hm~2 and 30 t/hm~2.The research conclusion indicates that (1) by-product from flue gas desulphurization has the effect of reclaiming soil physics and chemistry character, improving plant growth, and increasing plant yield. In the certain range (the amount of by-product from flue gas desulphurization less than 11.25 tons per hectare in strongly sodic soil, and 22.5 tons per hectare in sodic soil ), the reclaiming effect of sodic soil presents positive correlation with the used amount of by-product from flue gas desulphurization. If the amount exceeds the range, the better effect of reclaiming can't be attained and a great deal of salt will be accumulated, and increasing the difficulty of reclaiming sodic soil; (2) the used amount of by-product from flue gas desulphurization and sunflower yield don't present positive correlation. According to the experiment conclusion, when the plant yield reach maximum in strongly sodic soil and sodic soil, the used amount of by-product from flue gas desulphurization are 10.8 and 24.9 tons per hectare respectively. When the weight per one thousand of granules reaches the maximum, the amount of by-product from flue gas desulphurization are 11.1 and 25.2 tons per hectare respectively; (3)there exists a optimizing problem when by-product from flue gas desulphurization is employed in the field. In terms of this experiment result, the optimum used amount is between 1.3 and 1.5 times of the calculated amount.