An isotope study on Nitrogen and Phosphorus use efficiency and movement in soil in a mimicked vermicompost-based organo-mineral fertilizer

Vermicompost (VC), a stabilized organic material with high organic and humic carbon, and favorable aggregation properties, was tested as a fraction of organo-mineral fertilizers (OMFs), where organic and mineral fractions interact in hotspot areas with surrounding soil. Solutions containing 33P radioisotope and 15N labeled mineral fertilizers were combined with vermicompost at two ratios of organic carbon (Corg) to mineral nitrogen (N) and phosphorus (P) (OMF7.5C and OMF15C) to simulate OMF granules. Control treatments included unfertilized soil (N0P0), mineral fertilizer (MFNP), and sole vermicompost at 2 rates (OF7.5C and OF15C). Nitrogen and P uptake by Italian ryegrass (Lolium multiflorum) were measured over in 8 weeks. Furthermore, MFNP, OMF7.5C, and OMF15C treatments were incubated for 10 days without plant to measure atom% 15N excess and 33P radioactivity, as indicators of N and P movement from two soil layers (surrounding fertilizer hotspot and below it). In the pot study, OMF15..., Pot Experiment Setup
To assess N and P uptake by Italian ryegrass, a pot experiment was carried out for 8 weeks. Vermicompost (VC), a 15N-labeled N solution (Nsol) and a 33P-labeled P solution (Psol) were used to fertilize the soil and create the different treatments. A commercial vermicompost of bovine manure produced in Northwestern Italy was used in this study (Fig. S1). The commercial vermicompost was air-dried and milled to <2 mm. The vermicompost was characterized using the official methods of the Regione-Piemonte (1998). The residual humidity content of the dry vermicompost was 432 g kg-1, the pH in a water suspension (1:10) was 9.9, the Corg value in dry matter was 198 g kg-1 DM , the total P was 9 g kg-1 DM , and the total N was 14.8 g kg-1 DM. Ammonium sulfate ((NH4)2SO4) and potassium phosphate (KH2PO4) were used to prepare separate aqueous solution of 80.3 µg N ml-1 and 28.5 µg P ml-1, respectively. The Nsol was prepared by dissolving 9.57 mg of (NH4)2SO4 and 9.53 mg of 1..., , # An Isotope Study on Nitrogen and Phosphorus Use Efficiency and Movement in Soil in a Mimicked Vermicompost-based Organo-Mineral Fertilizer

The file \"Ryegrass_Pdff_Ndff\" contains the following sheets:

a) The \"solution preparation\" sheet indicates how the fertilizer solutions used in the experiment were prepared. The nutrient concentration is used in the sheets \"Pdff\" and \"Ndff\".

b) The \"Dry matter\" sheet indicates how the dry matter was calculated and their values are used in the sheets \"Pdff\" and \"Ndff\".

c) The \"SAfert\" sheet contains the values of specific activity of samples of mineral phosphorus solution. The values are used in the \"Pdff\" sheet\".

d) The \"GM\" sheet contains raw data about P measures with green malachite for P concentration in ryegrass samples. The values are used in the \"Pdff\" sheet.

e) The \"Pdff\" value contains the values of P concentration and specific activity of ryegrass samples and the calculations to determine the value of P derived from fertilizer (Pd...

# 基于模拟蚯蚓粪基有机-矿质肥料的土壤氮磷利用效率与运移同位素研究

蚯蚓粪（Vermicompost, VC）是一种富含有机碳与腐殖质碳、具备优良团聚特性的稳定有机物料，本研究将其作为有机-矿质肥料（organo-mineral fertilizers, OMFs）的组分开展试验，这类肥料的有机与矿质组分可在肥料热点区域及其周边土壤中发生相互作用。将含有³³P放射性同位素与¹⁵N标记矿质肥料的溶液，按照两种有机碳（Corg）与矿质氮（N）、磷（P）的配比与蚯蚓粪混合，以模拟有机-矿质肥料颗粒，分别记为OMF7.5C与OMF15C。对照组设置为不施肥土壤（N0P0）、单施矿质肥料（MFNP）以及两种施用量的单施蚯蚓粪处理（OF7.5C与OF15C）。本研究测定了多花黑麦草（Lolium multiflorum）在8周生长期内的氮、磷吸收量。此外，针对MFNP、OMF7.5C与OMF15C三个处理，本研究设置了无植物的10天培养试验，以测定原子百分比过量¹⁵N与³³P放射性活度，以此表征氮、磷在肥料热点区域周边及其下层两层土壤中的运移情况。

在盆栽试验中，OMF15…… 盆栽试验设置
为评估多花黑麦草的氮磷吸收量，本研究开展了为期8周的盆栽试验。试验所用物料包括蚯蚓粪（VC）、¹⁵N标记氮溶液（Nsol）与³³P标记磷溶液（Psol），用于土壤施肥并设置不同处理组。本研究采用意大利西北部生产的商用牛粪蚯蚓粪（见图S1）。该商用蚯蚓粪经风干后粉碎至粒径小于2 mm。参照皮埃蒙特大区（Regione-Piemonte）1998年发布的官方方法对蚯蚓粪进行了理化性质表征：风干蚯蚓粪的剩余含水率为432 g·kg⁻¹，水悬浮液（固液比1:10）的pH值为9.9，干物质中的有机碳（Corg）含量为198 g·kg⁻¹ DM，全磷含量为9 g·kg⁻¹ DM，全氮含量为14.8 g·kg⁻¹ DM。分别以硫酸铵((NH₄)₂SO₄)与磷酸二氢钾(KH₂PO₄)为原料，配制浓度为80.3 μg N·mL⁻¹的氮溶液与28.5 μg P·mL⁻¹的磷溶液。氮溶液（Nsol）的配制方法为称取9.57 mg硫酸铵与9.53 mg的1……

文件"Ryegrass_Pdff_Ndff"包含以下工作表：
a) "溶液配制"工作表：说明试验所用肥料溶液的配制方法，其中的养分浓度参数将用于"Pdff"与"Ndff"工作表。
b) "干物质"工作表：说明干物质重量的计算方法，其计算结果将用于"Pdff"与"Ndff"工作表。
c) "SAfert"工作表：收录矿质磷溶液样品的比活度数值，该数据将用于"Pdff"工作表。
d) "GM"工作表：收录采用孔雀绿法测定黑麦草样品磷浓度的原始实验数据，该数据将用于"Pdff"工作表。
e) "Pdff"工作表：收录黑麦草样品的磷浓度与比活度数值，以及用于计算肥料来源磷（Pd……）的相关计算过程。