(1) Productive principle: The main function of farmland is to provide agricultural products and industrial raw materials such as grain, oilseeds and vegetables for human beings, and the output of products reflects the quality and performance of farmland. At the same time, reasonable farmland landscape pattern can enhance its production function, and high product output is also the result of excellent farmland landscape quality. The purpose of farmland landscape reconstruction is to rationally allocate "patches-corridors", reduce energy consumption and the number of non-production corridors, improve farmland matrix conditions and improve farmland ecological and economic benefits.
(2) The principle of sustainable utilization: sustainable utilization is an important symbol of cultivated land reclamation. The change of landscape pattern can change the quantity and intensity of nutrient transfer among landscape components [132]. The farmland landscape pattern is unreasonable and prone to soil erosion, soil salinization and soil nutrient loss. Productivity, safety, protection, feasibility and acceptability are also the basic goals of sustainable utilization of reclaimed farmland landscape, and they are indispensable.
(3) Biodiversity principle: In order to facilitate large-scale production, weeds and other plants in the field have been cleared, and the biodiversity of farmland has been reduced, although pests and diseases have been reduced to some extent, natural enemies of pests have also been reduced. The ecosystem planted with a single crop for a long time is easy to breed pests, such as Jilin Great Leaf Blight and Head Smut. Reasonable organization of farmland planting structure and rational allocation of farmland boundary shelterbelt structure can improve farmland biodiversity and stabilize farmland ecosystem. Therefore, farmland biodiversity is also an indispensable standard for its landscape quality.
(4) Aesthetic principle: With the development of modern science and technology, human beings are liberated from heavy labor and have more time to enjoy life and integrate with nature. At present, the non-artificial natural landscape is gradually decreasing and relatively remote, and it takes a long time to complete the sightseeing process. As a special tourism resource, farmland landscape can provide tourism service function and make up for the shortcomings in people's lives, which requires the reclaimed farmland landscape to have certain aesthetic value and become an important tourism resource.
Farmland landscape is a landscape object formed by the integration of man and nature. Man is not only the creator of farmland landscape, but also the subject of landscape feeling. Under the control of specific aesthetic values, the aesthetic value judgment of the surrounding landscape environment is formed, and the specific feeling of the beauty of nature or humanity is obtained [133]. One of the essence of landscape planning and design of reclaimed farmland is to create aesthetic value on the basis of application and protection.