Perennial crops are crops that are not tilled after harvest but planted and then harvested year after year without replanting the crop. Most used examples are fruit trees and berry bushes. What has not been developed yet fully is perennial cereal crops.
Cultural landscape before NbS have been implemented
Cultural landscape after NbS have been implemented
This NbS is used in all types of ecosystems. Soil types and climate influence the crop type that is used. There is a large variety of perennial crops from all over the world.
Perennial crops have the potential to counteract societal challenges mainly related to biodiversity enhancement, climate change mitigation and adaptation, food security, disaster and risk preparedness and water management. This is done through the following pathways:
Provision of permanent habitats for organisms, both below and above the ground
Increased soil organic carbon stock in the long term
Improved erosion control
Improved water-use and nutrient cycling efficiency
Perennial crops are not that different from annual crops other than in the type of management needed. At present there are mostly perennial fruit and berry crops, and a few well-developed perennial cereal and legume crops. Perennial crops are also used as complementary to annual crops. For instance, they can be part of an agroforestry setting with permanent crops in field edges or middle of fields in a kind of intercropping.
The largest benefits of perennial crops are the reduction of soil disturbance and a permanent cover of the soil, which binds carbon and benefits soil organisms, and reduces soil erosion. It also creates a stable environment for organisms that could be a part of the surrounding habitats in a better way. Perennial crops can better retain water and reduce nitrogen leakage. There can also be benefits for production on marginal lands.
This can also be a good complement to annual crops that need less machinery use in between harvests.
Some diseases can build up in perennial systems as there is no crop rotation, if not taken care of by careful management. One way of managing diseases and pests of perennial systems is to use mixtures of crop cultivars or species that vary in resistance.
Perennial crops like fruits and berries are well established crop types with known management systems. Other crop types such as legumes and especially cereals have less established knowledge about the management systems.
There is no special extra cost to perennial crops compared to annual crops.
Cox, C. M., K. A. Garrett, and W. W. Bockus. 2005. “Meeting the Challenge of Disease Management in Perennial Grain Cropping Systems.” Renewable Agriculture and Food Systems 20 (1): 15–24. doi:10.1079/RAF200495.
Picasso, Valentín D., E. Charles Brummer, Matt Liebman, Philip M. Dixon, and Brian J. Wilsey. 2011. “Diverse Perennial Crop Mixtures Sustain Higher Productivity over Time Based on Ecological Complementarity.” Renewable Agriculture and Food Systems 26 (04): 317–27. doi:10.1017/S1742170511000135.
Zhang, Yanming, Yongpeng Li, Luming Jiang, Chao Tian, Jilin Li, and Zhimin Xiao. 2011. “Potential of Perennial Crop on Environmental Sustainability of Agriculture.” Procedia Environmental Sciences, 2011 3rd International Conference on Environmental Science and Information Application Technology ESIAT 2011, 10 (January): 1141–47. doi:10.1016/j.proenv.2011.09.182.
