The crops, crop sequences, their interaction with farm resources and management techniques used on a particular agricultural land over a period of years are very important to derive benefits from a given resource base under a specific environmental condition.

Crop: Plants grown in association, sown (or planted) and also harvested by human being, are collectively known as crop. Crop plants have some economic values and there is an interaction or competition among the plants.

System is a set of principles or procedures according to which management is done; it is an organized scheme or method. A system is a group of interrelated or interacting elements (crops or livestock) that act according to a set of rules to form a unified whole.

Definition: Agro-forestry is a land use system where woody perennials (or trees) are deliberately grown in conjunction with field crops, horticultural crops and pasture, with the objective of meeting various requirements of the farmers from the farm; it also acts as an insurance against the risk of uncertain / abnormal weather condition

The main objective of cropping system is to utilize the available resources in an efficient manner. There are several indices to evaluate the yield advantage of cropping system and also to compare the efficiency of different cropping system in terms of land use.

Till date, there is no complete agreement on the terms used in cropping system. An attempt was made to standardize the terms and their usage at the symposium on Multiple Cropping held by the American Society of Agronomy, in Knoxville, Tennessee, during August, 1975. Some definitions published in the proceeding (Andrews and Kassam, 1976) which forms the basis for the improvement and additions of definitions made subsequently (Francis, 1989). The terms commonly used in cropping system and their definitions are given in the following paragraphs.

Sorjan, an indigenous technology of Indonesia, is a series of sinks or canals alternating with raised beds. Sorjan, developed by Indonesian farmers, is a system that constructs an alternate of deep sinks and raised beds. Its features can adapt to both dry and wet seasons. Rice is usually planted in the sinks and a wide variety of upland crops is grown in the raised beds.