Water Quality Field Station Biomass Dataset

<table> <tr> <td width="60%"> <img class="contentimg" src="/site/resources/2016/06/14133/Slide01.JPG" alt="image" width="400px" /> </td> <td width="40%"> The Water Quality Field Station (WQFS), a Purdue University Core Facility, is an in-field laboratory dedicated to the study of productivity and environmental impacts of rainfed, maize-based production systems, system variants and emerging alternatives. <p><br/></p> The biomass data included here are from the perennial grass treatments, selected corn treatments and sorghum. information about the facility and experiments is given below. </td> </tr> </table> <h2>Facility</h2> Established in 1992, the WQFS emphasizes synergies and tradeoffs between crop productivity, soil microbial diversity, and air and water quality as influenced by crop rotation and fertilizer N management. The facility is located at Purdue University's Agronomy Center for Research and Education (ACRE), West Lafayette, IN (40° 29' 55.20" N; 86° 59' 53.23" W; elevation 215 m). The soil series are Drummer silty clay loam (fine-silty, mixed, superactive, mesic Typic Endoaquoll) and Raub silt loam (fine-silty, mixed, superactive, mesic Aquic Argiudoll). The mean air temperature and annual precipitation at the site are 12°C and 950 mm, respectively (data from 1977 to 2006). Companion daily weather data are available from ACRE's weather station. A hallmark attribute of the WQFS is that within every treatment plot (10.8 by 48 m), a large drainage lysimeter (10.8 by 24.4 m) was constructed as a bottomless clay box to allow the collection of drainflow from a hydrologically isolated area of soil thereby permitting analyses of management impacts on losses of nutrients and other crop inputs to surface waters. Bentonite slurry was used to construct the walls of the clay box to a depth of 1.5 m; 0.1 m diameter agricultural drain tiles are installed at 0.9 m depth and all drainage water from a given plot is monitored continuously for drainage volume with composite samples collected on a 24-hr interval for constituent analyses. <h2>Experimental Design</h2> <img align="left" src="/site/resources/2016/06/14133/biomass2.png" alt="image" width="400px" /> The experimental design for the facility is a randomized complete-block design with four replicates and 12 treatments (48 separately drained treatment plots). Eleven agricultural treatments are complemented by a restored prairie grass (PG) treatment, which serves as an analog for a natural ecosystem (Trt 1). <br/><br/> The predominant species in Trt 1 is big bluestem (Andropogon gerardii Vitman). Between 1995 and 2006, all agricultural treatments include maize grown annually with no rotation to another crop (continuous corn (CC)) or maize grown in rotation with soybean (corn-soybean rotation (C/S)); in 2007/2008, a subset of treatments (Trt 2-5) were transitioned to candidate bioenergy systems (described elsewhere) with only one treatment retained in a maize-based system (Trt 3). <br/><br/> Fertilizer N treatments feature varying rates, sources and application timings. For CC, inorganic N fertilizer management systems are generally as follows: (i) 202 kg N ha-1 applied preplant (Trt 3, 1995 – 2006), (ii) 179 kg N ha-1 applied preplant (Trt 12, 1995 – 2012), and (iii) 157 kg N ha-1 applied in a sidedress application after stand establishment and before the V6 growth stage (Trt 5, 1995 – 2007). For C/S rotations, the inorganic N fertilizer management systems require pairs of treatment plots so that both crops are present every study year; N managements are generally as follows: (i) 179 kg N ha-1 applied preplant (Trt 2 and 4, 1995 – 2007/2006), (ii) 157 kg N ha-1 applied preplant (Trt 6 and 7, 1995 – 2012), and (iii) 135 kg N ha-1 applied in a sidedress application after stand establishment and before V6 (Trt 8 and 9, 1995 – 2012). From 1997 onward, the source of inorganic N fertilizer was urea ammonium nitrate (UAN, 28% N) knifed in. <br/><br/> Two additional CC treatments receive swine manure effluent as their source of N fertilizer with approximately 250 kg N ha-1 injected in the spring and fall to Trt 10 and 11, respectively. Liquid starter fertilizer containing N and P is applied to all corn plantings at a rate of 22 kg ha–1 N and 8 kg ha–1 P placed 5 cm to the side and 5 cm below the seed. Some deviation in these N managements occurred prior to 1997 and these deviations are noted in the data record. Thereafter, the management is maintained as described. The best commercial hybrids for the region are used in conjunction with best management practices for other nutrients and pest/pathogen and weed control </p> <nb:citations></nb:citations>

水质野外站（Water Quality Field Station, WQFS）是普渡大学（Purdue University）核心设施，作为野外实验室，专门致力于雨养型玉米种植系统、系统变体及新兴替代方案的生产力与环境影响研究。此处收录的生物量数据取自多年生牧草处理组、选定的玉米处理组与高粱组。有关该设施与实验的详细信息如下。

## 设施
该站始建于1992年，重点研究作物轮作与氮肥管理模式下，作物生产力、土壤微生物多样性与空气、水质之间的协同效应与权衡关系。设施坐落于印第安纳州西拉法叶市普渡大学农学研究与教育中心（Agronomy Center for Research and Education, ACRE），地理坐标为40°29'55.20"N，86°59'53.23"W，海拔215米。供试土壤系列为德拉默粉质黏壤土（Drummer silty clay loam，fine-silty, mixed, superactive, mesic Typic Endoaquoll）与劳布粉质壤土（Raub silt loam，fine-silty, mixed, superactive, mesic Aquic Argiudoll）。该站点1977年至2006年的平均气温为12℃，年降水量为950毫米。每日配套气象数据可从ACRE气象站获取。WQFS的标志性特征为：每个处理小区（10.8m×48m）内均设置1台尺寸为10.8m×24.4m的大型排水蒸渗仪（drainage lysimeter），采用无底黏土箱结构，可从水文隔离的土壤区域收集排水，进而分析管理措施对养分及其他作物投入物向地表水流失的影响。研究采用膨润土浆构筑黏土箱墙体，深度达1.5米；在0.9米深度处安装直径0.1米的农用排水瓦，持续监测各小区的排水量，并以24小时为间隔采集混合样本用于成分分析。

## 实验设计
该设施的实验设计为随机完全区组设计，设置4次重复，共12个处理组（对应48个独立排水的处理小区）。其中11个农业处理组搭配1个恢复草原牧草（Prairie Grass, PG）处理组（处理1），作为自然生态系统的参照。处理1的优势物种为大须芒草（Andropogon gerardii Vitman）。1995年至2006年间，所有农业处理组均采用全年连作玉米（continuous corn, CC）或玉米-大豆轮作（corn-soybean rotation, C/S）的种植模式；2007/2008年，部分处理组（处理2-5）被转换为候选生物能源系统（详见其他文献），仅保留1个基于玉米的种植系统（处理3）。

氮肥处理涵盖不同施用量、肥料类型与施用时期。对于连作玉米模式，无机氮肥管理方案通常如下：(i) 播前施用202千克氮/公顷（处理3，1995-2006年）；(ii) 播前施用179千克氮/公顷（处理12，1995-2012年）；(iii) 在出苗后、V6生育期前采用条施方式施用157千克氮/公顷（处理5，1995-2007年）。对于玉米-大豆轮作模式，无机氮肥管理需成对设置处理小区，以保证每个研究年度均可同时种植两种作物，其管理方案通常如下：(i) 播前施用179千克氮/公顷（处理2和4，1995-2007/2006年）；(ii) 播前施用157千克氮/公顷（处理6和7，1995-2012年）；(iii) 在出苗后、V6生育期前条施135千克氮/公顷（处理8和9，1995-2012年）。1997年起，无机氮肥采用尿素硝酸铵溶液（urea ammonium nitrate, UAN，含氮28%）进行深施。

另有2个连作玉米处理组采用猪粪废水作为氮源，分别于春季和秋季施入约250千克氮/公顷（对应处理10和11）。所有玉米种植均施用含氮磷的液态种肥，施用量为22千克氮/公顷与8千克磷/公顷，施肥位置为种子侧方5厘米、下方5厘米处。1997年之前的氮肥管理存在部分偏差，相关细节已在数据记录中注明，此后均按上述方案执行。实验采用适配本区域的优良商业杂交品种，并配合其他养分、病虫害与杂草防控的最佳管理措施。