膨润土对燕麦苗期土壤水分及生物学性状的影响

The effects of bentonite on soil moisture and biological characteristics of oat at seedling stage

为明确膨润土对黄土高原旱作土壤保水改土效果,设计试验:施用量0 kg·hm^(-2)(CK)、6 000 kg·hm^(-2)(D1)、12 000 kg·hm^(-2)(D2)、18 000 kg·hm^(-2)(D3)、24 000 kg·hm^(-2)(D4)、30 000 kg·hm^(-2)(D5);2011年一次性施入,2012—2015年研究其对燕麦苗期土壤含水量、微生物量碳、氮和土壤酶活性的影响。结果表明,膨润土各施用量均能提高燕麦出苗率,2012年D2、D3处理最佳,较对照提高了11.41%、8.93%;2013年D3、D4处理表现较好,较对照提高了8.39%、5.56%;2014年表现为D4、D5处理较对照提高了10.25%、8.32%;2015年表现为D4、D5处理较对照提高了8.71%、7.48%。同时,发现施用膨润土可提高苗期0~100 cm土层土壤含水量,尤以10~20 cm土层变化最显著,较对照提高1.21%~40.76%。施用膨润土能显著增加2012—2015年0~10 cm土层土壤微生物生物量碳、氮含量、土壤过氧化氢酶、蔗糖酶和脲酶活性,可分别较CK增加2.92%~31.42%、5.05%~47.15%、4.75%~45.89%、2.73%~49.91%、6.67%~70.00%。可见,膨润土能够显著改善耕层土壤的保水性和持水性、改善土壤生物性学性状,且其效果具有一定的长效性,随着施用年限增加,高施用量处理效果最显著。

To investigate the role of bentonite soil supplement on water retention and soil amelioration as well asseedling protection in the dry farming regions of Inner Mongolia Loess Plateau, a field experiment with （0（ C K ） , and 6 000（D1） , 12 000（D2） , 18 000（D3） , 24 000（D4） and 30 000 kg ·hm ^-2（D5））of bentonite was applied. After one-time application in 2011, the effects of application rates on oat seeding characterization and soil moisture content, micro-bial biomass carbon, microbial biomass nitrogen and soil enzyme activity were examined in 2012-2015. The results showed that one-time application can improve the emergence rate, in 2012, D2 and D3 were higher than that of control with 11.41% and 8.93% respectively; in 2013, D3 and D4 were higher than that of control with 8.39 %, 5.56 % re -spectively ;performance in 2014,D4 and D5 compared with the control improved （ in c re a se d ） to 10.25% and 8.32% respectively; in 2015 D4 and D5, were 8.71 %, 7.48 % respectively h ig h er than the c o n tro l. One-time a p p lica tio n o f bentonite raised soil water content in the soil profile （0 ~ 100 cm） , with the most significant increase of 1 . 21 % - 40.76% at the 10 ~ 20 cm layer. Compared to the CK treatment, bentonite increased soil microbial biomass carbon （2.92% ？31.42%）,ni t rogen（5.05% -47.15%）,catalase （4.75% -4 5 .8 9 %）,invertase （2.73% -49.91%） , urease （6.67% -70.00%） in the top 10 cm soi l. It was concluded that the application of bentonite canprove soil water retention, water holding capacity and soil biological traits in the plough layer during the oat seedling growth period. With time, the long-lasting effect of higher application rates of bentonite became more evident.