在定期耕作的土壤中，維持並增加**土壤有機質（SOM）**是農民面臨的共同挑戰，通常需要結合多種方法。對於不養殖牲畜的農場（Stock-free farms）而言，重複施用堆肥、種植豆科牧草以及綠肥，雖然能維持或提升有機質含量，但這類做法若非得在場內自行堆肥（耗費空間與時間），就是得從外部採購（成本高且不符合永續原則）。
使用來自樹木或樹籬管理的木屑提供了一個替代方案：木屑可以經過堆肥處理，也可以直接以「鮮切木屑（RCW, Ramial Chipped Wood）」的形式施用。若能在作物輪作的適當時機使用，木屑能顯著增加土壤有機質、持水能力及養分含量。
有機研究中心（The ORC）領導了「木屑肥沃土壤計畫（WOOdchip for Fertile Soils）」，旨在研究如何將 RCW 作為年度農藝與園藝生產的永續有機質來源，並鼓勵農民將農場內的木本元素管理納入整體農場系統。為期三年的農場田間試驗結果已收錄於技術指南中，其中重點關注物流與經濟效益（詳見延伸閱讀 2）：
農民選擇 RCW 而非堆肥的時機： 當無法自行製作堆肥、缺乏可用堆肥或儲存空間，以及希望達成農場投入物自給自足時。
規模效益與限制： 隨著處理量增加，採用大型高效機械會使砍伐（矮林作業）與粉碎的單位成本降低；然而，大型農企業的運作模式通常缺乏改變的靈活性，難以採用手作或小型機械的作業方式。
RCW 最具經濟效益的情境：
- 為了翻新老舊樹籬而進行矮林化修剪時。
- 當地木屑供應有限、價格昂貴或品質難以保證時。
- 管理樹木或樹籬以獲取木材時，產生了剩餘的枝條。
雖然 RCW 和堆肥都能增加土壤有機質，但兩者對土壤的影響各異，可以採取互補方式共同使用。
原文：
Sustaining and building soil organic matter (SOM) on regularly cultivated soils is a common challenge for farmers who often combine different methods to do so. Repeated compost applications alongside using legume leys and green manures can maintain or enhance SOM levels on stock-free farms but requires producing and composting on-farm (taking up space and time) or sourcing externally (costly and unsustainable). Using woodchip produced from tree and hedge management is an alternative; either composted or applied fresh as Ramial Chipped Wood (RCW). When used at an appropriate phase in a crop rotation it can increase SOM, water holding capacity and soil nutrient levels.
The ORC led the WOOdchip for Fertile Soils project to investigate using RCW as a sustainable source of organic matter for annual arable and horticultural production, encouraging farmers to manage woody elements on the farm as part of a whole farm system. Observations and results from 3 years of on-farm field trials are outlined in
technical guides and include a focus on logistics and economics – see Further reading 2:
• Farmers may choose RCW over compost when unable to produce compost, available compost or storage space is lacking, and / or they want to be input self-sufficient.
• Coppicing and chipping become cheaper per unit as volume increases and using larger more efficient machines becomes viable, but the scale of larger farming enterprises often creates less flexibility to change and adapt, ruling out doing things by hand or with smaller machines.
• RCW often makes most economic sense:
– when coppicing to rejuvenate an old hedgerow
– where local woodchip supply is limited, costly and/or quality cannot be assured
– where hedge / tree management for logs produces brash not otherwise used.
Although both RCW and compost add to the SOM, they have different effects on the soil and
can be used in a complimentary way.