中国北方主要棉区土壤供钾能力及其与产量和品质的关系

2012―2013年在山东平原县、河北威县、新疆昌吉市代表性棉田上采集土壤(0~20 cm)和棉花样品,分析北方棉区土壤钾素状况、供钾能力及其与棉花产量和纤维品质的关系。结果表明,平原、威县、昌吉棉田速效钾含量平均分别为217、128、232 mg·kg-1,供钾能力平均分别为128.2、105.1、213.6 kg·hm-2,每生产100 kg皮棉棉花地上部分别吸收K 9.77、7.82、12.25 kg。不同棉区土壤速效钾含量与皮棉产量和地上部吸钾量相关性不同,在平原和昌吉,当土壤速效钾含量分别小于123 mg·kg-1和220 mg·kg-1时,与皮棉产量和地上部吸钾量具有显著正相关。3个植棉区棉花的吸钾量与子棉产量、皮棉产量都呈显著的正相关。棉花地上部吸钾量、纤维吸钾量和纤维含钾量与纤维品质指标的相关性不同地点差异大。

Soil Potassium Supply Capacity in Relation to Cotton Yield and Fiber Quality in Major Cotton Producing Areas in North China

To determine the soil potassium status and supply capacity as well as their relation to cotton yield and quality in major cotton areas in north China, surface soil (0-20 cm), cotton plant and lint samples were collected and analyzed from representative cotton fields in Pingyuan County of Shandong Province, Weixian County of Hebei Province and Changji City of Xinjiang Province in 2012 and 2013. In Pingyuan County, more than 50% of the soil samples had 100-200 mg· kg^－1 soil available K and 23% of samples had more than 300 mg·kg^－1, with an average of 217 mg·kg^－1. In Weixian County, 53% of soil samples had 100-150 mg·kg^－1 soil available K and 22% of samples had less than 100 mg·kg^－1, with a mean of 128 mg·kg^－1. In Changji, more than 2/3 of samples had soil available K of 150-300 mg·kg^－1 and 25% of samples had more than 300 mg·kg^－1, with an average of 232 mg·kg^－1. The soil K supply capacity, represented by uptake K of aboveground organs, was 120-140 kg·hm^－2 in 68% of sites with a mean of 128.2 kg·hm^－2 in Pingyuan County, 80-120 kg·hm^－2 in 65% of sites with a mean of 105.1 kg·hm^－2 in Weixian County, and 150-300 kg·hm^－2 in 92% of sites with an average of 213.6 kg·hm^－2 in Changji City. The average K uptake by aboveground organs required to produce 100 kg of lint cotton was 9.77, 7.82 and 12.25 kg, respectively, in Pingyuan County, Weixian County and Changji City. In Pingyuan County, significant positive correlations existed between soil available K and lint cotton yield, plant K uptake when the soil available K was less than 123 mg·kg^－1. In Weixian County, there were no significant correlations between soil available K and lint cotton yield, plant K uptake. In Changji, significant positive correlationsexisted between soil available K and lint cotton yield, plant K uptake when the soil available K was less than 220 mg·kg^－1. The correlations between plant K uptake and cotton yield varied by location, but there were significant positive correlations between lint K uptake and cotton yield in all three sites. There were great variations in the relationships between plant K uptake, lint K uptake, lint K content and fiber quality indices in different locations.