摘要： 为探明深松措施下磷肥施用深度对春玉米根系特性的影响，实现根系与磷素在空间上充分耦合，可为玉米高产栽培磷肥合理运筹提供科学依据，采用裂区设计，以耕作方式为主区，副区为施磷深度，研究深松措施下不同施磷深度不同春玉米品种的根系生物量、比根长和根系活力，并分析其与产量的相关性。结果表明：旋耕措施下，0~20 cm土层根干质量吐丝期P12和P18较高，乳熟期P12较高，P24吐丝期低于P6而乳熟期高于P6；20~60 cm土层吐丝期和乳熟期磷肥深施处理均高于P6，以P12最高。深松+旋耕措施下，0～20 cm土层春玉米根干质量吐丝期施磷深度处理均高于正常施磷P6，0～20 cm土层乳熟期和20~60 cm土层吐丝期和乳熟期均为P12和P18较高。旋耕措施下0～20 cm和40～60 cm土层比根长P12最大，与P6差异显著，20~40 cm土层P24最高。旋耕措施下3个土层根系活力和0~20 cm，40~60 cm比根长均表现为P12最高，深松+旋耕措施下根系活力除20~40 cm吐丝期外，P12与P18差异不显著，均高于P6，比根长0～20 cm土层吐丝期和乳熟期P12最高，P24最低，40~60 cm土层P12和P18差异不显著，P12高于P6和P24。除吐丝期20～60 cm土层根系生物量外，2个生育期各土层根干质量、比根长和根系活力与产量呈显著、极显著相关，根系干质量和比根长主要影响因素是深松和磷肥施用深度，根系活力与深松密切相关。综上，春玉米总根干质量、比根长和根系活力与产量呈正相关，总体表现为深松+旋耕>旋耕措施，磷肥施用深度在旋耕措施下12 cm左右较为适宜，在深松+旋耕措施下12～18 cm较为适宜。

关键词: 春玉米, 深松, 磷肥施用深度, 根系特性

Abstract: To reveal the effects of phosphorus placement depth on root characteristics of spring maize under the subsoiling measures, achieve adequate spatial coupling between root system and phosphorus, to provide scientific basis for the rational operation of high yield phosphate fertilizer in maize cultivation, the root biomass, specific root length and root activity of maize with different phosphorus placement depth were studied, and the correlation between the indicators and yield was analyzed by means of the split plot design. In the main area of tillage practices, rotary tillage and subsoiling plus rotary tillage were set up, and the secondary area was phosphorus placement depth with 6 (P6, normal phosphorus placement depth), 12 (P12), 18 (P18), and 24 cm (P24) treatments. The results showed that the P12 and P18 treatments at silking stage and P12 treatment at milking stage in root dry weight of spring maize in 0-20 cm soil layers under rotary tillage measure. But the P24 treatment showed lower and higher root dry weight compared with P6 at silking stage and milking period, respectively. In 20-60 cm soil layers, the root dry weight of three phosphorus treatments were heavier than P6 at silking stage and milking stage, and the P12 treatment reached the highest value. Under subsoiling plus rotary tillage measures, three phosphorus treatments in the root dry weight at silking stage were heavier than P6. In 0-20 cm soil layers, the P12 and P18 treatments showed higher root dry weight at milking stage. Similarly, better performances also were found in P12 and P18 treatments in 20-60 cm soil layers at silking stage and milking stage. Under rotary tillage condition, the P12 treatment, significantly differing from P6, had the biggest specific root length in 0-20 cm and 40-60 cm soil layers at two stages. However, the P24 treatment had the highest value in 20-40 cm soil layers. To specific root activity in three soil layers and root length in 0-20 cm and 40-60 cm soil layers, the P12 treatment showed the highest value under rotary tillage. Under subsoiling plus rotary tillage condition, except for the root activity of 20-40 cm soil layer at silking stage, P18 were significantly differ from P12,they were higer than P6. The P12 treatments showed highest specific root length in 0-20 cm, and the P24 treatment was lowset at silking stage and milking, P18 were no significantly differ from P12 in 40-60 cm soil layers, the P12 was higer than P6 and P24. The changing trends of the root biomass, specific root length and root activity of two spring maize varieties were basically the same. Except for the root biomass of 20-60 cm soil layer at silking stage, the root dry weight, specific root length and root activity of various soil layer were significantly correlated with yield at two growth stages. The correlation analysis suggested that the root biomass and specific root length at milking stage were mainly affected by the subsoiling treatment and phosphorus placement depth, and the higher root activity of each soil layer was closely related to the subsoiling treatment. In conclusion, the root dry weight, specific root length and root activity of various soil layer were significantly correlated with yield at two growth stages;the subsoiling plus rotary tillage treatment was better than rotary tillage;the phosphorus placement depth was suitable for 12 cm under rotary tillage treatment and 12-18 cm for subsoiling plus rotary tillage treatment.

Key words: Spring maize, Subsoiling, Phosphorus placement depth, Root characteristics

中图分类号: 

• S513.01

• S143.2