Agroforestry systems and understory harvest management: the impact on growth and productivity of dual-purpose wheat

Abstract: The objective of the study was to evaluate the growth and production efficiency of forage-grain dual-purpose wheat in two arrangements and four agroforestry systems (Intercrop-I and Intercrop-II), as well as to evaluate crop management for the wheat crops in two planting seasons (Crop Season I-2014 and Crop Season II-2015. The experiment was conducted in a randomized complete block design, factorial scheme 7x2x2, with seven cultivation systems Eucalyptus urophylla x Eucalyptus grandis Intercrop-II and Intercrop-I; Peltophorum dubium Intercrop-II and Intercrop-I; P. rigida Intercrop-I; S. parahyba Intercrop-I; a wheat monoculture with no tree species present; and two harvest management techniques (with and without harvesting of the forage species). Agroforestry systems generated shading for wheat plants, with a higher phyllochron and lower values of leaf area index of those individuals kept under trees with higher crown shading (non-deciduous trees) due to the lower transmissivity of solar radiation. The systems composed with Schizolobium parahyba in Intercrop-I and Parapiptadenia rigida in Intercrop-I provide a minor phyllochron to the wheat, resulting in a higher leaf area index and dry matter yield. Thus, the cultivation of tree species and dual-skilled agricultural crops, such as wheat, provides promising alternatives for the future use of land in tropical countries.摘要：本研究旨在评估两种配置模式、四类农林业系统下粮饲兼用小麦的生长状况与生产效率（间作I型、间作II型），同时探究两个种植季（2014年种植季I、2015年种植季II）中小麦的田间管理方案效果。实验采用随机完全区组设计（randomized complete block design），因子试验方案为7×2×2，共涵盖7种栽培系统：尾叶桉×巨桉（Eucalyptus urophylla × Eucalyptus grandis）间作I型、间作II型；盾柱木（Peltophorum dubium）间作I型、间作II型；硬皮黄檀（Parapiptadenia rigida，原文缩写为P. rigida）间作I型；巴西苏木（Schizolobium parahyba，原文缩写为S. parahyba）间作I型；以及无乔木伴生的小麦单作系统；另设置2种收获管理措施：饲草刈割组与非刈割组。农林业系统会为小麦植株提供遮荫环境，在冠层遮荫能力更强的非落叶乔木下栽培的小麦，其叶序期（phyllochron）更长，叶面积指数（leaf area index）更低，这是由于该生境的太阳辐射透过率更低所致。其中，巴西苏木间作I型与硬皮黄檀间作I型系统下的小麦叶序期更短，进而拥有更高的叶面积指数与干物质产量（dry matter yield）。综上，搭配乔木物种与粮饲兼用作物（如小麦）的栽培模式，为热带国家的土地可持续利用提供了极具前景的替代方案。