Monitoring of soil fertility in Eucalyptus 12ABL plantation was based on the fertilization test, which continued for five years. The tseatment 1 (N1P1K1), 8 (N3P3K1) and 9 (N3P3K2) were selected as the monitoring sites from 9 different fertilizer plots. The investigation results were as follows: The pH value in the soil reduced from 5.17 before planting to about 4.6, and the organic matter content of soil changed slightly, which was lower in the treatment 1 than in others. The total N contents of the soil were lower than before planting in all treatments. The total P contents of the soil were similar to the background, and the K contents of the soil in the treatment 8, 9 were higher than before planting, but which was lower in treatment 1. The available N contents of the soil were lower after planting than before planting, especially in the treatment 1. The available P content of soil decreased after planting in the treatment 1, which was similar to background in other treatments. The available K contents of soil were higher after planting than before planting in all treatments, which was more obvious in the treatment 9. The exchangeable Ca contents of the soil in the treatment 8, 9 were lower after planting than before planting, especially in the treatment 9. The highest current increment in height growth occurred in the second year after planting for the treatment 9, which was in the third year after planting for the treatment 8, and treatment 1. The litter was positively correlated to the tree increment. The pulpwood produced per hectare was 2073.55 kg, 4807.88kg, and 5054.52kg in the treatment 1, treatment 8, and treatment 9 respectively. The monitoring result showed that Eucalyptus growth was related to the environment, especially it was closely related to the soil habitat.
Soil fertility and growth increment of Pinus massoniana Lamb. trees were monitored for 5 years in a young stand located in Fenyi county, Jiangxi Province. The results showed that the effect of fertilization with K was not evident, but that was better with P. The content of total P in soil in the second year, in the third year, and the fifth year after fertilization increased 18.2%, 18.1%, and 43.1% respectively, compared with control. The height, DBH and volume of forest trees in the plot fertilized with P yearly increased 3.0%, 16.7% and 9.7% comparing with control, suggesting positive effect of P fertilizer applied in the hill and mountainous districts with red soil.
在湖北省江汉平原选择有代表性的3种土壤立地,进行南方型杨树氮、磷、钾常规肥料多点施肥试验(1991~1995)。结果表明:施氮肥能显著促进杨树生长,单施磷、钾肥效应均不好;平原粘湿土壤还呈显著负效应,只宜单施氮肥;平原冲积土、湖区沉积土立地均以氮+磷混施效应最佳。优化施肥量:平原粘湿土立地按400kgN/hm2、平原冲积土立地按200kgN/hm2+100kg2O5、湖区沉积土立地按100kgN/hm2+100kgP2O5/hm2,折算成尿素和过磷酸钙。5年提高蓄积生长量35%~75%,纯增益6000~11000元/hm2。
本文报道了施肥4年对杨树人工林土壤养分的消长、水分物理特性及土壤微生物的影响。结果表明,施肥可提高土壤有机质,全N、速效N含量,其最适处理(100kgN/hm2+100kgP2O5/hm2)分别比施肥前提高21%、60%和14%;而施肥对全P、速效P以及土壤水分物理特性影响不大;对各处理土壤微生物的分析表明,施肥使土壤微生物总数比造林前提高了37.7%,从而提高土壤活性,促进林木生长。适当地施肥并不会对土壤理化性质和生态环境造成剧烈的影响。
1991~1995年期间,在江西景德镇市低丘千枚岩和第4纪红土红壤上,研究了火炬松、湿地松幼林施肥(P和PK)对土壤性质和叶片养分的影响。结果表明:(1) 2个施肥处理使火炬松和湿地松林土壤速效P含量提高,有机质等其它土壤肥力指标下降。施P肥加速了有机质矿化和林木对N的吸收; (2) 2个施肥处理能提高湿地松林土壤细菌、真菌和纤维分解菌的数量,减少放线菌的数目,而施肥前期对好气固N菌、P细菌有促进作用,后期对其有抑制作用; (3) 2个施肥处理能明显提高湿地松林土壤脲酶和过氧化氢酶活性,施肥前期磷酸酶活性受到抑制,施肥后期磷酸酶活性不再受抑,酶活性大大提高。P肥能提高蔗糖酶活性,而PK肥对蔗糖酶活性有抑制作用; (4)湿地松林施肥2年后,叶片养分有明显变化, P和PK处理提高了叶片Ca、Mg的含量,降低了N水平,而对P和K含量影响不大。
为了解造林后杉木林地土壤肥力的变化情况及施肥对林地土壤肥力的影响,经对杉木中心产区土壤肥力中等的杉木林地设固定样地,进行土壤肥力的观测研究。结果表明,杉木林地施肥后土壤的理化性质得到了明显的改善。施肥后第2年,土壤的含P量, P2和P2K1处理分别比对照提高了13%和21%,而P2K1处理的速效和缓效K比对照提高了20%和19.5%;施肥后第4年其含P量分别高25%和28%,而P2K1处理的速效和缓效K比对照提高了21%和29%;造林后,随着林龄的增加杉木林地的土壤肥力呈逐年下降的趋势。造林5年后,离树干距离40cm的土壤含N、P、K肥的下降比例较树干距离80cm的低。
The results of soil monitoring in the fourth year of plantation indicate that afforestation with Chinese fir leads to the decrease in contents of organic matter, rapidly available phosphorus, rapidly available potassium, hydrolytic acid, exchangeable Mg2+, moreover leads to the decrease of pH value, so that, the soil fertility of forest land tends to degeneration, however fertilization can avoid soil degeneration and improve soil fertility of the forest land. When calcium magnesium phosphate is used as base fertilizer, soil fertility indexes, such as organic matter, rapidly available nitrogen, rapidly available phosphorus, rapidly available potassium, exchangeable Ca2+, exchangeable Mg2+ and the pH value can be increased. The results also show that the increase of soil fertility indexes is related with the amount of calcium magneaium phosphate applied. The contents of the 5 main nutrients in leaves of Chinese fir sapling are related with the season and the stand age. The contents of all the nutrients in winter are higher than those in summer, as the age of stand increases, the content of total nitrogen decreases while that of total phosphorus, total potassium, total calcium, total magnesium increases.
对设置于江西分宜县中国林科院亚林中心5组不同整地方式水土流失多年观测结果进行了综合分析。地表径流量从1.47~13.22 mm,平均为5.46 mm。径流系数从0.098%~0.852%,平均为0.369%,年均土壤侵蚀量从0.0051~0.2510 t/hm2,平均为0.1005 t/hm2。整个幼龄林阶段,地表径流量546.0 m3/hm2,土壤侵蚀总量为1005.0 kg/hm2;养分损失量:N1.9560 kg/hm2, P2.2370 kg/hm2, K26.777 kg/hm2,有机质50.049 kg/hm2。分析认为在板、页岩风化物上发育的黄红壤,特别是腐植质层较厚结构良好的土壤,具有较强的抗腐蚀能力,不管采用哪种整地方式均无明显的水土流失和养分损失,但比较而言,以穴垦为最佳选择。水土流失还不是此种土壤上杉木人工林的地力退化的最主要的原因。
本文对设置在世界银行贷款“国家造林项目”13个项目省(区)内10个主要造林树种新造速生丰产林地上的34个土壤肥力定位观测点上连续5年观测取得的资料和数据进行了综合分析。分析结果表明,造林后土壤中各类养分含量逐年变化程度不一,相比之下,土壤速效N、P、K含量的变幅较大,而土壤有机质和全N含量变幅较小。施肥对“土壤速效养分下降型”土壤中的速效N、P、K含量提高较显著,提高幅度对于速效P相对较大,对于速效N相对较小。建议通过土壤肥力观测确定施肥方案,侧重对“土壤速效养分下降型”土壤进行施肥。
(月刊 1955年创刊) 主管:中国科学技术协会 主办:中国林学会 出版:《林业科学》编辑部 主编:尹伟伦 国内统一刊号:CN 11-1908/S 国际标准刊号:ISSN 1001-7488 国内邮发代号:82-6