Growing winter cereal rye (Secale cereale) (WCR) has been identified as an effective in-field practice to reduce nitrate-N and phosphorus (P) losses to Upper Mississippi River Basin, USA. In the Midwestern USA, growers are reluctant to plant WCR especially prior to corn (Zea mays L.) due to N immobilization and establishment issues. Precision planting of WCR or ‘skipping the corn row’ (STCR) can minimize some issues associated with WCR ahead of corn while reducing cover crop seed costs. The objective of this study was to compare the effectiveness of ‘STCR’ vs normal planting of WCR at full seeding rate (NP) on WCR biomass, nutrient uptake and composition in three site-yrs (ARC2019, ARC2020, BRC2020). Our results indicated no differences in cover crop dry matter biomass production between the STCR (2.40 Mg ha−1) and NP (2.41 Mg ha−1) supported by similar normalized difference vegetative index and plant height for both treatments. Phosphorus, potassium (K), calcium (Ca) and magnesium (Mg) accumulation in aboveground biomass was only influenced by site-yr and both STCR and NP removed similar amount of P, K, Ca and Mg indicating STCR could be as effective as NP in accumulating nutrients. Aboveground carbon (C) content (1086.26 kg h−1 average over the two treatments) was similar between the two treatments and only influenced by site-yr differences. Lignin, lignin:N and C:N ratios were higher in STCR than NP in one out of three site-yrs (ARC2019) indicating greater chance of N immobilization when WCR was planted later than usual. Implementing STCR saved $8.4 ha−1 for growers and could incentivize growers to adopt this practice. Future research should evaluate corn response to STCR compared with NP and assess if soil quality declines by STCR practice over time.

中文翻译：

---

精准种植对冬季谷物黑麦生长、养分吸收、春季土壤温度和采用成本的影响

种植冬季谷物黑麦（黑麦) (WCR) 已被确定为一种有效的现场实践，可减少美国密西西比河流域上游的硝酸盐-N 和磷 (P) 损失。在美国中西部，种植者不愿意种植 WCR，尤其是在玉米之前（玉米L.) 由于 N 的固定和建立问题。WCR 的精确种植或“跳过玉米行”（STCR）可以最大限度地减少与玉米之前的 WCR 相关的一些问题，同时降低覆盖作物的种子成本。本研究的目的是在三个地点年（ARC2019、ARC2020、BRC2020）比较“STCR”与以全播种率 (NP) 正常种植 WCR 对 WCR 生物量、养分吸收和组成的有效性。我们的结果表明 STCR 之间的覆盖作物干物质生物量产量没有差异（2.40 Mg ha-1) 和 NP (2.41 毫克/公顷-1) 得到两种处理的相似归一化营养指数和株高的支持。地上生物量中的磷、钾 (K)、钙 (Ca) 和镁 (Mg) 积累仅受地点年的影响，STCR 和 NP 都去除了相似量的 P、K、Ca 和 Mg，表明 STCR 可能与NP 在积累养分。地上碳 (C) 含量 (1086.26 kg h-1两种处理的平均值）在两种处理之间相似，并且仅受地点-年份差异的影响。在三分之一的地点年（ARC2019）中，STCR 中的木质素、木质素：N 和 C：N 比率高于 NP，这表明当 WCR 的种植时间比平时晚时，N 固定的机会更大。实施 STCR 节省了 8.4 美元公顷-1对于种植者，并可以激励种植者采用这种做法。未来的研究应与 NP 相比评估玉米对 STCR 的反应，并评估 STCR 实践是否会随着时间的推移土壤质量下降。