不同覆沙厚度下松嫩平原盐碱裸地上的种植效果

松嫩平原土地盐碱化严重限制了当地农牧业的可持续发展,覆沙并在覆沙层种植作物是盐碱化土地的有效利用途径。为此在松嫩平原盐碱裸地上进行不同厚度覆沙(10、20、30、40 cm),并连续2年分别种植玉米(Zea mays)、向日葵(Helianthus annuus)、大麦(Hordeum vulgare)及苜蓿(Medicago sativa)(第2年补播),探究不同厚度覆沙4种作物的种植效果。结果表明,覆沙后第1年种植4种作物均能生长,但长势较弱,第2年长势较强。覆沙40 cm玉米产量为5621 kg·hm^?2,是覆沙10 cm的3.27倍(P<0.05),但与覆沙20、30 cm差异不显著(P>0.05)。覆沙30 cm苜蓿的干草产量和根干重高于其他覆沙厚度,分别达8597和3367 kg·hm^?2,且分别是覆沙10 cm的3.00倍(P<0.05)和1.29倍(P<0.05)。覆沙40 cm向日葵和大麦籽粒产量显著高于覆沙10 cm,分别提高33.4%和269.5%,而覆沙20、30 cm与覆沙10 cm之间差异不显著(P>0.05)。因此,覆沙后种植玉米和苜蓿分别推荐覆沙20 cm以上和覆沙30 cm;种植向日葵和大麦推荐覆沙40 cm。研究结果表明,盐碱裸地上覆沙可成功种植作物。

Effects of different sand-cover thicknesses on crops in bare saline-alkali land in the Songnen Plain

The salinization of the Songnen Plain seriously restricts the sustainable development of farming and animal husbandry.Sand-covering and planting crops on the sand layer are effective methods to utilize salinized land.To study the effects of different sand-cover thicknesses on different crops,maize,sunflower,barley,and alfalfa were planted on bare saline-alkaline land with sand-cover thicknesses of 10,20,30,and 40 cm in the Songneng Plain.All four crops grew normally in the first year after sand-covering but grew weakly at the settlement stage.In the second year,all four crops grew powerfully.Sand-cover of over 20 cm significantly promoted maize growth.Maize yield was 4298 kg·ha?1 with sand-cover of 40 cm,which was 2.5 times higher than that with sand-cover of 10 cm(P<0.05).The hay yield and total root biomass of alfalfa were the highest with sand-cover of 30 cm,and reached 8597 and 3367 kg·ha?1,respectively;these were 3.36 and 1.28 times higher than those with sand-cover of 10 cm(both P<0.05).The yields of sunflower and barley were highest with sand-cover of 40 cm;these were 33.4%and 269.5%higher than those with sand-cover of 10 cm,respectively.However,there were no significant differences among sand-cover thicknesses of 20 cm,30 cm,and 40 cm.Therefore,maize should be planted with sand-cover of more than 20 cm,alfalfa with sand-cover of 30 cm,and sunflower and barley with sand-cover of 40 cm.The results show that these crops can be grown successfully by sand-covering in saline-alkali land.