覆沙对松嫩平原盐碱裸地的改良和利用效果研究

本文研究不同覆沙厚度及覆沙后种植农作物和饲草对松嫩平原盐碱裸地的改良和利用效果。结果表明：覆沙后沙土层土壤含水量、pH和电导率明显低于盐碱土层,且随沙土深度的增加而增加,在同一沙土层随覆沙厚度的增加而降低。不同厚度覆沙后表层盐碱土电导率由初始621 μS/cm降低至389~594 μS/cm。2013年覆沙30 cm玉米产量较2012年高51.1%,且比覆沙20 cm高32.29% (P<0.05),比覆沙40 cm低8.9% (P>0.05)。2013年覆沙30 cm紫花苜蓿产量和总根生物量分别是2012年的2.04倍和3.65倍,总根生物量较覆沙20 cm和覆沙40 cm显著增加55.9%和106.3%。2012年和2013年覆沙30 cm种植紫花苜蓿沙土层电导率分别降低23.1%和43.5%。不同厚度覆沙对盐碱地有一定改良作用,覆沙后连续2年种植玉米和紫花苜蓿增产效果显著,推荐覆沙30 cm。

The Improvement and Utilization of Bare Saline-alkali Soil in the Songnen Plain by Sand-covering

The improvement and utilization of bare saline-alkali soil in the Songnen Plain were studied by different thickness of sand-covering and planting corps or forages. Two years results showed that SWC, pH and EC in sandy soil layer were significantly lower than that of saline-alkali soil layer, and increased with sandy soil depth. SWC, pH and EC in the same sandy soil layer decreased with the increase of sand-covering thickness. EC of surface saline-alkali soil was reduced from 621 μS/cm to 389-594 μS/cm under different sand-covering thickness treatments. The yield of maize with sand-covering of 30 cm in 2013 was 51.1% higher than that of 2012, and was 32.29% higher than that of sand-covering of 20 cm (P<0.05) and 8.9% lower than that of sand-covering of 40 cm (P>0.05), respectively. The yield and total root biomass of alfalfa with sand-covering of 30 cm in 2013 was 2.04 times and 3.65 times that of 2012, respectively. The yield of alfalfa with sand-covering of 30 cm was not significantly different from that of sand-covering of 20 cm and sand-covering of 40 cm, but the total root biomass of alfalfa increased by 55.9% and 106.3%, respectively. EC of alfalfa in sandy soil layer was decreased by 23.1% and 43.5% in 2012 and 2013 respectively under the sand-covering of 30 cm. Therefore, sand-covering has some improvement effects on saline-alkali soil, and planting maize and alfalfa under sand-covering of 30 cm has remarkable effects on yields.