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><table> <tr> <td width="60%"> <img class="contentimg" src="/site/resources/2016/06/14133/Slide01.JPG" alt="image" width="400px" /> </td> <td width="40%"> 水质野外站（Water Quality Field Station, WQFS）是普渡大学（Purdue University）核心设施之一，为田间原位实验室，专注于雨养型玉米种植生产系统、系统变体及新兴替代模式的生产力与环境影响研究。<p><br/></p> 本次收录的生物量数据源自多年生牧草处理组、选定的玉米处理组及高粱样本。有关该设施与试验的详细信息如下。 </td> </tr> </table> <h2>设施概况</h2> 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大气、水环境质量之间的协同效应与权衡关系。站点位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），地理坐标为北纬40°29'55.20"、西经86°59'53.23"，海拔215米。供试土壤包括Drummer粉质粘壤土（细粉质、混合型、高活性、温性普通潜育暗瘠土）与Raub粉质壤土（细粉质、混合型、高活性、温性水成淋溶暗瘠土）。该站点1977-2006年的年均气温为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。水质野外站的标志性特征为：每个处理小区（10.8米×48米）内均设置1个大型排水渗漏计（drainage lysimeter，10.8米×24.4米），该渗漏计为无底黏土箱结构，可收集水文隔离区域土壤的排水流量，从而能够分析田间管理措施对养分及其他作物投入物向地表水体流失的影响。黏土箱的墙体采用膨润土泥浆构筑，深度达1.5米；在0.9米深度处铺设直径0.1米的农用排水瓦管，每个小区的所有排水均会持续监测排水量，并以24小时间隔采集混合样本用于成分分析。 <h2>试验设计</h2> <img align="left" src="/site/resources/2016/06/14133/biomass2.png" alt="image" width="400px" /> 本设施的试验采用完全随机区组设计，设置4次重复，共12个处理（对应48个独立排水的处理小区）。其中11个农业处理组辅以1个恢复草原牧草（restored prairie grass, PG）处理组，作为自然生态系统的对照（处理组1，Trt 1）。处理组1的优势物种为大须芒草（Andropogon gerardii Vitman）。1995-2006年间，所有农业处理组均采用每年单一种植玉米（连作玉米，continuous corn, CC），或玉米与大豆轮作（玉米-大豆轮作，corn-soybean rotation, C/S）的模式；2007/2008年，部分处理组（Trt 2-5）被调整为候选生物能源系统（详见其他说明），仅保留1个基于玉米的种植系统（Trt 3）。氮肥处理设置了不同的施用量、肥源与施用时机。针对连作玉米模式，无机氮肥管理模式通常分为以下三类：(1) 播前施用202 kg·ha⁻¹氮肥（Trt 3，1995-2006年）；(2) 播前施用179 kg·ha⁻¹氮肥（Trt 12，1995-2012年）；(3) 在齐苗后、V6生育期前进行侧施，施用157 kg·ha⁻¹氮肥（Trt 5，1995-2007年）。对于玉米-大豆轮作模式，无机氮肥管理需设置成对的处理小区，以保证每个试验年度内两种作物均有种植；其氮肥管理模式通常分为以下三类：(1) 播前施用179 kg·ha⁻¹氮肥（Trt 2、4，1995-2007/2006年）；(2) 播前施用157 kg·ha⁻¹氮肥（Trt 6、7，1995-2012年）；(3) 在齐苗后、V6生育期前进行侧施，施用135 kg·ha⁻¹氮肥（Trt 8、9，1995-2012年）。1997年起，无机氮肥肥源采用脲铵氮肥（urea ammonium nitrate, UAN，含氮28%），采用沟施方式施用。另有2个连作玉米处理组采用生猪粪污液作为氮肥源，分别在春季和秋季注入约250 kg·ha⁻¹氮肥（对应Trt 10和Trt 11）。所有玉米种植地块均施用含氮磷的液态种肥，施用量为每公顷22 kg氮与8 kg磷，肥液施加位置为种子侧方5 cm、下方5 cm处。1997年之前的氮肥管理存在部分偏差，相关偏差已在数据记录中注明。1997年之后，管理模式均按上述标准执行。试验采用本地区最优商业化玉米杂交品种，并配合其他养分管理、病虫草害防控的最佳管理措施。 <nb:citations></nb:citations>