Effects of three amendments on the soil properties of and maize growth in coastal saline-alkali soils

This study explored the effects of different soil amendments-a calcium preparation(GZJ), furfural residue(KQZ), and weathered coal(FHM)on the improvement of moderately saline-alkali coastal soil and maize growth therein. The effects of the treatments on the physicochemical properties of the soil and on maize plant height, chlorophyll content(SPAD), and yield were studied via pot experiments, and the experimental dosage of each treatment was as follows:GZJ1(15 t·hm-2), GZJ2(22.5 t·hm-2), KQZ1(30 t·hm-2), KQZ2(45 t·hm-2), FHM1(30 t·hm-2), and FHM2(45 t·hm-2). The results showed that the three amendments significantly increased the cation exchange capacity(CEC) of saline-alkali soil by 17.53%~49.45%, compared to when no amendments were added. Three amendments reduced soil bulk density and salt content while two different doses of furfural slag and high levels of weathered coal reduced soil bulk density significantly by 7.80%~12.06%. Two different doses of weathered coal and a low dose of the calcium preparation reduced the soil salt content significantly by 13.19%~19.33%. In addition, the calcium preparation and furfural residue significantly increased the quantity of water-stable aggregates(0.25~0.5 mm and 0.5~1 mm, respectively), increasing these by 5.36~6.59 percentage points and 1.92~2.81 percentage points, respectively. The quantity of micro-aggregates(-2 of furfural residue). Furfural slag and weathered coal significantly increased the plant height and SPAD of maize at different stages. The height of the maize plant at maturity increased by 9.71%~13.09% and the SPAD at jointing stage increased by 10.13%~16.44%. The three amendments increased the number of grains per ear and yield per plant by 15.97%~37.43% and 25.86%~49.65%, respectively; Once again, treatment KQZ1 had the best effect. The calcium preparation, furfural slag, and weathered coal all improved the moderately saline-alkali coastal soil and the kernel number and yield of maize. However, there was no significant difference between the three kinds of amendments in different dosages. The comprehensive effect of improvement with the use of furfural slag was better than those with the use of weathered coal and the calcium preparation; and treatment KQZ1 (30 t·hm-2)had the best comprehensive improvement effect among the furfural slag treatments.