The effects of organic matter amendments (OMA) on soil fertility in permanent cropping systems like orchards is under-studied compared to annual cropping systems. We evaluated experimentally the impact of OMAs on soil fertility in almond (Prunus dulcis) orchards over a two-year period with annual applications. Two OMAs, derived from composted green waste (GWC) or composted manure wood chips (MWC), were applied as surface mulch and compared to a control at two sites with different soil textures (sandy loam and loamy sand). OMAs increased soil moisture content (0–0.1 m depth) at both sites by 27–37%. Both amendments increased soil inorganic N at the sandy loam (GWC: 194%; MWC: 114%) and loamy sand (GWC: 277%; MWC: 114%) sites the month following application, but soil inorganic N concentrations quickly decreased to values similar to those of control plots. After two-years, the GWC and the MWC amendments increased the soil cation exchange capacity (CEC) by 112% and 29%, respectively, in the sandy loam site, but no change was observed in the loamy sand site. The greatest increase in soil extractable K occurred in the GWC-amended plots at the sandy loam site even though the initial K concentration of MWC was higher. Both OMAs increased soil organic carbon (SOC) after two years, but the SOC increase in the GWC-amended plots was greater. Our results suggest that OMAs can significantly improve soil fertility after one or two annual applications, and that fertility gains appear to be dependent on soil texture than the nutrient concentrations of the OMA.

与一年生种植系统相比，有机质改良剂 (OMA) 对果园等永久性种植系统土壤肥力的影响研究不足。我们通过实验评估了 OMA 对杏仁 ( Prunus dulcis)土壤肥力的影响) 果园两年内每年申请。两种来自堆肥绿色废物 (GWC) 或堆肥木屑 (MWC) 的 OMA 被用作表面覆盖物，并在具有不同土壤质地的两个地点（砂壤土和壤土）与对照进行比较。OMA 将两个地点的土壤水分含量（0-0.1 m 深度）提高了 27-37%。施用后一个月，两种改良剂都增加了沙壤土（GWC：194%；MWC：114%）和壤土（GWC：277%；MWC：114%）地点的土壤无机氮，但土壤无机氮浓度迅速下降至数值类似于控制图。两年后，GWC 和 MWC 改良剂使砂壤土的土壤阳离子交换容量（CEC）分别增加了 112% 和 29%，但在壤砂土中没有观察到变化。尽管 MWC 的初始 K 浓度较高，但土壤可提取 K 的最大增加发生在砂壤土的 GWC 修正地块中。两年后，两种 OMA 都增加了土壤有机碳 (SOC)，但 GWC 修正地块中的 SOC 增加更大。我们的结果表明，OMA 可以在每年施用一两次后显着提高土壤肥力，并且肥力的增加似乎取决于土壤质地，而不是 OMA 的养分浓度。