棕壤花生镁营养特性对不同耕作措施的响应

Response of Peanut Magnesium Nutrition Characteristics to Various Tillage Measures in Brown Soils

为探究不同耕作措施下花生镁(Mg)营养特性变化,利用鲁东3个典型棕壤花生田试验点(望城、夏甸和齐山)开展耕作试验,研究免耕、浅耕20 cm、深耕30 cm和深松30 cm下花生镁吸收特征、土壤交换性镁临界值,以及镁吸收与产量、品质和磷协同吸收的关系。结果表明,3个试验点花生植株总镁吸收量以深耕30 cm处理最高,浅耕20 cm和深松30 cm处理次之,免耕处理最低。花生荚果部分镁吸收量(6.7～11.8 kg·hm^(-2))低于根茎叶针等其他部分镁吸收量(18.9～31.9 kg·hm^(-2)),且免耕较相应耕作处理降低21.2%～36.7%。荚果镁的吸收显著促进了花生产量的增加及品质的提升,总体表现为荚果镁吸收量每增加1.0 kg·hm^(-2),花生产量可增加500 kg·hm^(-2),同时花生含油量、蛋白质含量、蔗糖含量、百果重、百仁重分别增加196.0、83.4、15.7、14.0和6.4 kg·hm^(-2)。随着花生镁吸收量的增加,磷吸收量也显著增加(P<0.01),且荚果中磷对镁的响应程度大于根茎叶针等其他部分磷对镁的响应程度。一元二次方程模拟结果表明,典型棕壤花生田土壤交换性镁的临界值下限为402 mg·kg^(-1),低于下限值花生荚果镁及总镁吸收量随土壤交换性镁含量的增加而增加;而当土壤交换性镁超过455 mg·kg^(-1)时,花生镁吸收量与土壤交换性镁之间关系不显著,不再随之增加。综上,深耕等有效耕作措施可显著改善花生镁营养状况,有利于促进镁与磷的协同吸收,提高花生产量及品质。本研究结果为花生田镁营养合理管理提供了理论依据。

In order to investigate the changes in the magnesium（Mg） nutrition characteristics for peanut（Arachis hypogaea L.） under various soil tillage measures, no tillage, shallow plough 20 cm, deep plough 30 cm（DP）, and deep loosing 30 cm were carried out in three typical brown soil experimental sites of Wangcheng, Xiadian and Qishan, which were used to study the Mg absorption characteristics, critical value of soil exchangeable Mg, and the relationships of Mg absorption with yield, quality and phosphorus（P） absorption. Results showed that total Mg absorption amount was highest under DP, following by SP and DL, and NT was the lowest. Pod Mg uptake amounts（6.7～11.8 kg·hm^-2） were lower than other parts of root, stem, leaf and peg（18.9～31.9 kg·hm^-2）, while NT was of 21.2～36.7% lower than other three treatments. Higher pod Mg absorption amounts significantly positively contributed to higher yields and better qualities. With each increase of 1.0 kg·hm^-2 in pod Mg absorption amount, peanut yield was increased by 500 kg·hm^-2, while contents of oil, protein, sucrose, 100-pod weight, and 100-kernel weight were increased by 196.0, 83.4, 15.7, 14.0 and 6.4 kg·hm^-2, respectively. The increase of Mg absorption amount in peanut extremely significantly promoted the P absorption amount as well（P 0.01）, and the response rate was higher in pod than other parts of peanut. A quadratic equation simulated well the relationship between soil exchangeable Mg content and peanut Mg absorption amount. The lower limit of critical value for soil exchangeable Mg content was 402 mg·kg^-1, while peanut pod and total Mg absorption amounts increased as it was lower than the critical value. When soil exchangeable Mg content exceeded the high limit value of 455 mg·kg^-1, peanut Mg absorption amount was not increased continuously. In short, improving the peanut Mg nutrition by appropriate tillage measures such as deep plough contribute to the synergistic absorption of Mg and P, which further enhanced peanut yield and quality. The present study provides a theoretical basis for rational Mg nutrition management in peanut field.