长期施用有机肥对松嫩平原西部盐碱土壤肥力和玉米产量的影响

依据施用有机肥（腐熟牛粪）年限的不同，共设置4个不同处理，分别为：施用有机肥13 a（13A）、19 a（19A）和24 a（24A）,以未施用有机肥的盐碱土作为对照（CK）,采集各处理0～20 cm和20～40 cm的土壤样品，测定土壤养分、物理性状和盐碱性质，旨在探明长期施用有机肥措施下苏打盐碱土壤的肥力状况及其促进玉米产量提升的机制。结果表明：与CK相比，施用有机肥显著提高了0～20、20～40 cm土层的土壤有机质、全氮、速效养分含量和土壤田间持水量（P<0.05）,显著降低了土壤容重和土壤密度（P<0.05）,显著增加了0～20 cm土层的土壤孔隙度（P<0.05）。0～20 cm土层中，土壤有机质、全氮以19A处理最高，分别达39.31 g·kg^-1和1.30 g·kg^-1;土壤碱解氮、速效磷、速效钾均以24A含量最高，较CK分别提高了89.31%、81.07%和107.64%,土壤孔隙度以24A含量最高，较CK提高了54.56%,各处理土壤容重和土壤密度平均较CK下降率达31.91%和6.29%,处理间不显著。...

Effects of long\|term application of cattle manure on soil fertility and corn yield of saline\|sodic soil in western Songnen Plain

Based on the number of years of cattle manure application, four different treatments were set in this study. The treatments included 13 years (13A), 19 years (19A) and 24 years (24A) of applying cattle manure, and the saline\|sodic soil without applying cattle manure was used as control (CK). Soil samples of 0~20 cm and 20~40 cm in each treatment were collected to determine soil nutrients, physical properties and saline\|sodic properties to explore the fertility of saline\|sodic soil and the mechanism of increasing corn yield under long\|term application of cattle manure. The results showed as follows: Compared with CK, cattle manure application significantly increased the contents of soil organic matter, total nitrogen, available nutrients and soil field water capacity in 0~20 cm and 20~40 cm layers (P<0.05) and significantly decreased the soil bulk density and soil density (P<0.05) as well as significantly increased the soil porosity in 0~20 cm layer (P<0.05). In 0~20 cm soil layer, soil organic matter and total nitrogen were the highest under 19A treatment, reaching 39.31 g·kg^-1 and 1.30 g·kg^-1, respectively. The content of available nitrogen, available phosphorus and available potassium reached the highest at 24A, which increased by 89.31%, 81.07% and 107.64% compared with CK. The content of soil porosity reached the highest at 24A, which increased by 54.56% when compared with CK. The average decrease rate of soil bulk density and soil density of each treatment was 31.91% and 6.29% compared with CK, however, there were no significant differences between treatments. At the same time, the soil pH, electrical conductivity (EC) and alkalinity (ESP) of all treatments were significantly lower than those of CK (P<0.05). In 0~20 cm soil layer, the soil pH value was the lowest at 24A, which was 24.45% lower than that of CK. The EC and ESP were the lowest in 19A treatment, which decreased to 0.14 dS·m^-1 and 2.52%, respectively. The improvement effect of organic fertilizer on soil physical and chemical properties was more obvious with the increase of application years. The corn yield of treatment for 24A was the highest, reaching 13 780 kg·hm^-2, which was increased by 58.57% compared with CK, and significant difference was found among all treatments (P<0.05). The corn yield of CK was the lowest (8 690 kg·hm^-2). The results of structural equation model analysis showed that after long\|term application of cattle manure fertilizer, soil field capacity, total nitrogen content, and soil organic matter content were increased, soil bulk density was decreased, and soil pH value was changed. As a result, the corn yield was increased. The decrease of soil bulk density and the increase of field water holding capacity were the key factors affecting corn yield.