Remediation of a mine soil with insoluble polyacrylate polymers enhances soil quality and plant growth

We investigated the effects of different application rates of insoluble hydrophilic polyacrylate polymers on plant growth and soil quality from a Pb‐contaminated mine soil. The polymer increased the water‐holding capacity of the soil from about 250 g/kg in unamended soil to almost 1000 g/kg in soil with 0.6% polymer. However, the capacity of the polymer to retain water decreased progressively, presumably as the polymer sorbed Pb. Growth of orchardgrass (Dactylis glomerata L. cv. Amba) was stimulated in the polymer‐amended soil. The greatest accumulated biomass over four cuts was obtained in soil amended with 0.4% of polymer. After orchardgrass had been growing for 101 days, the amounts of CaCl₂‐extractable Pb present in the polymer‐amended soil were 15–66% of those in the unamended soil, depending on polymer application rate. The number of bacteria culturable on agar enriched with ‘Nutrient’ and yeast extract, and the activities of dehydrogenase, phosphatase, β‐glucosidase, protease and cellulase increased following polymer application. In contrast, urease activity was impaired by polymer application, presumably due to the presence of ammonium as a counter ion. Principal component analysis was used to compare the effects of the different rates of polymer application. Overall, the application of 0.2 or 0.4% polymer resulted in closer values for the indicators of soil quality used than the treatment with 0.6% polymer.     

不同施氮量和时间对鸭茅生产利用的影响

鸭茅是温带地区优良牧草,是需肥最多的禾本科牧草之一。氮肥在鸭茅的生长发育过程中起着相当重要的作用,不同的氮肥施用方式是影响鸭茅生产如饲草产量、种子产量及其品质等方面的重要因素。因此,研究鸭茅的氮肥营养,开发适宜鸭茅的牧草用肥,制定合理的施肥措施,对于提高鸭茅种子品质、牧草产量和质量具有现实意义。     

西藏拉萨地区不同施氮量对鸭茅产量的影响

在西藏拉萨地区进行不同施氮量(尿素)对鸭茅产量的影响研究。结果表明,鲜(干)草产量、种子产量、植株生长速度随施氮量的增加而明显提高,但当施氮达到一定量时,其产量不再提高,反而呈下降趋势。7个处理的鲜(干)草产量均显著高于对照,尿素施量160~240 kg/hm2的鲜(干)草产量保持在较高水平,施量160 kg/hm2的鲜(干)草产量最高;施尿素的鸭茅种子产量与未施者差异显著,施量160~280 kg/hm2的鸭茅种子产量较高;施量120~200 kg/hm2的鸭茅生长速度明显高于其他施肥水平;对于牧草高效生产的经济效益而言,尿素施量为160 kg/hm2的处理能够获得最大经济效益。     

10个鸭茅品种在川中丘陵地区的适应性研究

为筛选出在川中丘陵地区生态适应性强的鸭茅（Dactylis glomerata L.）品种,于2015-2016年在四川省遂宁市河沙镇和天保镇对10个鸭茅品种进行生产性能的比较研究。结果表明,在河沙镇,鸭茅株高最高的品种为‘滇北’（133.87 cm）,分蘖数及干草总产量最高的为‘奥拉沃’（71.91个·株^-1,6 653 kg·hm^-2）;在天保镇,鸭茅株高和分蘖数最高的品种均为‘金牛’,干草总产量最高的为‘斯巴达’（6 206 kg·hm^-2）;在营养品质上,‘金牛’的粗蛋白含量最高,为18.35%,其次为‘滇北’（17.31%）和‘奥拉沃’（16.31%）;可溶性碳水化合物含量最高的为‘宝兴’,为9.01%;‘奥拉沃’和‘宝兴’的中性洗涤纤维含量显著低于其他品种（P<0.05）。隶属函数分析表明,‘滇北’和‘奥拉沃’具有较高的隶属函数值,‘金牛’及‘宝兴’次之,均能够较好地适应川中丘陵区的自然环境条件,适宜在该区推广。     

鸭茅EST-SSR标记在4种禾草上的可转移性

为了检验鸭茅EST-SSR标记在几种禾本科植物上的可转移性并筛选出可应用于后续研究的引物,本研究用40对可在鸭茅(Dactylis glomerata)上扩增产物的鸭茅EST-SSR引物,分析了6份多花黑麦草(Lolium multiflorum)、6份高羊茅(Festuca arundinacea)、3份扁穗牛鞭草(Hemarthria compressa)和3份牛鞭草(H.altissima)共18份材料的转移率、遗传多样性和亲缘关系。结果表明,多年生黑麦草和高羊茅可转移率为60%,扁穗牛鞭草和牛鞭草转移率最低,均为50%,26对引物共获得条带128条,多态性条带121条,多态性比(PPB)为94.53%,平均扩增出多态性条带4.92条,平均多态性信息量0.952。18份材料遗传相似系数范围为0.208~0.974,在遗传系数为0.68时,4个物种分别独自聚为一大类。本研究证实利用鸭茅EST序列开发的EST-SSR在有一定亲缘关系的物种间转移是可行的,可转移的引物对未来禾本科遗传育种研究有一定的参考价值。