撒施石灰石粉對(duì)橡膠樹(shù)細(xì)根空間分布及季節(jié)動(dòng)態(tài)的影響

王真輝　劉季　胡義鈺　孫亮　陳秋波　袁坤

摘 要 土壤酸化對(duì)橡膠樹(shù)細(xì)根生長(zhǎng)具有嚴(yán)重影響。為了解橡膠樹(shù)細(xì)根生長(zhǎng)對(duì)土壤酸度改變的響應(yīng)，本研究在熱研7-33-97未開(kāi)割（7 a）、開(kāi)割5 a、開(kāi)割10 a共3個(gè)膠園選取樣樹(shù)，采用撒施石灰石粉的方式進(jìn)行土壤酸度改良，并用土鉆法觀測(cè)橡膠樹(shù)根系對(duì)土壤酸度改變的響應(yīng)。結(jié)果顯示：同一割齡膠園中土壤酸化改良植株（改良組）與對(duì)照植株（對(duì)照組）相比，其細(xì)根生物總量顯著增加，且均符合開(kāi)割5 a膠園的最高，開(kāi)割10 a膠園的最低這一規(guī)律。酸性土壤改良后橡膠樹(shù)細(xì)根在垂直與水平方向生物量均有所增加，分布規(guī)律無(wú)明顯改變。不同割齡膠園改良組與對(duì)照組中橡膠樹(shù)細(xì)根年內(nèi)變化趨勢(shì)均為單峰型，峰值出現(xiàn)在當(dāng)年7～9月，年變化規(guī)律無(wú)明顯改變。本研究結(jié)果表明，膠園酸性土壤經(jīng)施用石灰石粉后橡膠樹(shù)的細(xì)根生長(zhǎng)量提高，有利于橡膠樹(shù)從土壤中吸收更多的水分和養(yǎng)分，從而改善橡膠樹(shù)的生長(zhǎng)和提高其產(chǎn)量。

關(guān)鍵詞 橡膠樹(shù)；細(xì)根；生物量；石灰石粉

中圖分類號(hào) S794.1 文獻(xiàn)標(biāo)識(shí)碼 A

Influence of Limestone Powder Doses on the Fine Root Spatial Distribution and Seasonal Dynamics of Hevea brasiliensis

WANG Zhenhui1，LIU Ji1，2，HU Yiyu1，SUN Liang1，CHEN Qiubo1，YUAN Kun1*

1 Rubber Research Institute， Key Laboratory of Biology and Genetic Resources of Rubber Tree，

Ministry of Agriculture， Danzhou， Hainan 571737， China

2 College of Agriculture， Hainan University， Haikou， Hainan 570100， China

Abstract Soil acidification has great implications on the fine root growth of rubber tree. To understand the response of fine root growth to the change of soil acidity， the growth performance of the fine roots were evaluated in limestone application treatments and no limestone-addition controls in the period from March 2012 to January 2013 by using sequential root coring methods. The hevea clone used was Reyan 7-33-97 at the ages of 7 a （not tapping yet）， 12 a （being tapped for 5 years）and 17 a（being tapped for 10 years）. The results indicated that there was significant difference in root biomass between the treatments and the controls in all the tree ages. The most remarkable effects in increment of fine root biomass was recorded in the trees of 12 years old that had been tapped for 5 years， while the least increment effects in the trees of 17 years old which had been apped for 10 years. The vertical distribution of the fine roots varied with tree ages， but shared the same pattern as the soil depth increased the fine roots dencity decreased to give lower percentage in the total fine root biomass. Horizontally， the fine root distribution varied between the treatments and the controls among different age groups. In any case the fine root biomass of rubber trees was found to increase somewhat either vertically or horizontally with the application of limestone on the surface of acid soil under rubber tree at different ages. The annual variation of the total fine root biomass of rubber trees including both the treatments and the controls showed a one-peak type. However， the occurrence of the peak was not all in the same months. For those trees of 7 years old and 12 years old the peak appeared in July while for those trees of 17 years old in September. No uniform patterns were observed on the fine root biomass of different soil layers under rubber trees of varied ages， but the emergernce of the peak of varied soil layers coincided with that of the total fine root biomass without any exception. It is therefore concluded that amendment of soil pH through the application of limestone is encouraged for the sake of higher fine root growth and turnover to enable rubber trees to uptake more nutrients and water from the soils for better growth and yield of the trees.

Key words Hevea brasiliensis；Fine root；Biomass；Limestone

doi 10.3969/j.issn.1000-2561.2015.01.001

在森林生態(tài)系統(tǒng)中，細(xì)根的生長(zhǎng)和周轉(zhuǎn)是森林生態(tài)系統(tǒng)物質(zhì)循環(huán)和能量流動(dòng)的一個(gè)重要組成部分[1]，細(xì)根周轉(zhuǎn)對(duì)樹(shù)木體內(nèi)碳和養(yǎng)分循環(huán)具有重要的影響[2]，通過(guò)生物量的定期變化體現(xiàn)出來(lái)。

中國(guó)在20世紀(jì)50～60年代已經(jīng)開(kāi)始橡膠樹(shù)根系生長(zhǎng)和分布的研究[3]，而土壤環(huán)境條件對(duì)橡膠樹(shù)細(xì)根生長(zhǎng)動(dòng)態(tài)及周轉(zhuǎn)影響的研究尚未充分展開(kāi)。林希昊等[4-6]研究了不……