植物生态学报

• •    

基于多物候指标的人工牧草长势监测及产量估测

严文秀1,赵诗晗1,郑春燕2,张萍1,沈海花3,常锦峰1,徐亢4   

  1. 1. 浙江大学环境与资源学院
    2. 中国科学院遗传与发育生物学研究所农业资源研究中心
    3. 中国科学院植物研究所
    4. 无锡学院
  • 收稿日期:2024-05-24 修回日期:2024-08-09 发布日期:2024-09-01

Growth monitoring and yield estimation of artificial forage based on multiple phenological metrics

  • Received:2024-05-24 Revised:2024-08-09

摘要: 随着精准农业的发展,实时监测和准确预测作物的生长状况及产量变得至关重要。但是,传统的监测方法往往受限于时间、人力和成本等因素,难以满足现代农业管理的需求。研究旨在利用物候相机对人工牧草进行长势监测,并提取物候指标来进行产量估测。利用不同肥度处理下青贮玉米和燕麦的物候照片和无人机影像分别提取绿度指数GCC、归一化植被指数NDVI以及叶片叶绿素指数LCI,通过GCC进行植被生长曲线拟合并计算出物候指标;并利用线性拟合分析物候指标与两种人工牧草株高与产量指标之间的关系,构建出物候指标对收获指标的最佳拟合模型并根据R2占比计算相对解释度。主要结果:(1)施氮量影响人工牧草的物候指标和收获指标,高肥处理下的青贮玉米和中肥处理下的燕麦生长期长度最长(分别是68 ? 5天和59 ? 1天),相应的产量最高(分别是1903.22 ? 284.62 kg/亩和345.38 ? 129.27 kg/亩);(2)GCC、LCI与人工牧草株高的相关性最好,尤其是在GCC达到POP峰值前(POP前R2分别是0.86和0.49),且GCC对青贮玉米的株高动态捕捉偏差最小;(3)人工牧草物候指标能有效预测实测的最大株高和最终产量(青贮玉米R2分别是0.328和0.829,燕麦R2分别是0.975和0.935),本研究证实了基于物候相机和无人机影像的物候指数在监测人工牧草物生长状况和产量的有效性。

关键词: 物候相机, 绿度指数, 物候指标, 产量估测, 归一化植被指数

Abstract: Aims With the development of precision agriculture, real-time monitoring and accurate prediction of crop growth status and yield have become crucial. However, traditional monitoring methods are often limited by factors such as time, manpower, and cost, making it difficult to meet the needs of modern agricultural management. The aim of this study was to use PhenoCam to monitor the growth of artificial forage and extract phenological metrics to estimate the yield. Methods GCC, NDVI and LCI were extracted from phenological photos and UAV images of silage maize and oat under different fertility treatments. The phenological metrics were calculated by fitting and combining the vegetation growth curves of GCC. The relationship between phenological metrics and plant height and yield of two kinds of artificial forage was studied by linear fitting, and the best fitting model of phenological metrics to harvest characteristic was constructed. Important findings (1) Nitrogen application rate drove the phenological metrics and harvest characteristic of artificial forage. The growing period length of maize silage under high fertilizer treatment and oat under medium fertilizer treatment was the longest (68?5 days and 59?1 days), and the corresponding yield was the highest (1903.22?284.62 kg/ mu and 345.38?129.27 kg/ mu, respectively). (2) GCC and LCI had the best correlation with the plant height of artificial forage, especially before GCC reached the peak POP (pre-POP R2 was 0.86 and 0.49), and GCC had the smallest deviation in dynamic capture of plant height of silage maize. (3) The phenological metrics of artificial herbage can effectively predict the measured maximum plant height and final yield (R2 of silage maize were 0.328 and 0.829, and R2 of oat were 0.995 and 0.935). This study confirmed the effectiveness of phenological metrics based on Phenocam and UAV images in monitoring the growth status and yield of artificial forage grass.

Key words: Phenocam, GCC, phenological metrics, yield estimation, normalized difference vegetation index (NDVI)