Simulation of Best Management Practices for Soybean Production in Hawaii

The study showed that an agronomic model and economic analysis are useful tools for agricultural decision-making in Hawaii. Crop models shortened the time needed to test and determine suitable management schemes to produce crops in specific locations on the North Shore of Oahu

APPLICATIONS OF DECISION SUPPORT SYSTEM FOR AGROTECHNOLOGY TRANSFER IN PRESENT DAY AGRICULTURE

The Decision Support System for Agrotechnology Transfer (DSSAT) is an interactive, user-friendly, microcomputer-based software package designed to assist scientists, policymakers, and resource planners in rapidly accessing a natural resource data base, evaluating predicted outcomes, and prescribing solutions to site-specific problems. It is a powerful tool for enhancing the efficiency of agricultural research and assessing new agrotechnology packages in the rapidly changing and exacting environments in which farmers have to operate. The DSSAT, developed by a team of international scientists under the auspices of the IBSNAT Project, consists of a data base management system, crop simulation models for cereals and grain legumes, and application programs. Its application on agricultural, environmental, and global issues offers valuable assistance in decisionmaking and long-term strategic planning

Chapter 1: Managing Fertilizer Nutrients to Protect the Environment and Human Health

The goal of a nutrient management plan is to ensure the availability of adequate nutrients for crop production with minimal nutrient loss in runoff or leaching from the root zone. Such a plan should include an evaluation of site environmental concerns, evaluation of available soil nutrient status, calculation of nutrient application amounts based on realistic crop yields and available soil nutrients, and, appropriate nutrient application methods. This chapter explains how fertilizer nutrients can be environmental pollutants and, in some cases, a danger to human health. It describes the evolution of regulations designed to protect society from this pollution, and it provides details about what goes into a nutrient management plan

Simulating Inbred-Maize Yields with CERES-IM

CERES-Maize, which was designed for simulation of hybrid maize (Zea mays L.), cannot be applied directly to seed-producing inbred maize because of specific field operations and physiological traits of inbred maize plants. We developed CERES-IM, a modified version of CERES-Maize 3.0 that accommodates these inbred-specific operations and traits, using a set of phenological measurements conducted in Nebraska (NE), and further tested this model with a set of field data from Michigan (MI). Detasseling (i.e., removal of the tassels from the female plants) was conducted prior to silking. Male rows were removed approximately 10 d following 75% silking. The thermal time from emergence to the end of the juvenile phase (P1) and the potential number of kernels per plant (G2) were assessed from field data, and were the only two coefficients allowed to vary according to the inbred line. Rate of leaf appearance of the inbreds was accurately simulated using a measured phyllochron interval of 54 degree-days (°Cd). Simulation of detasseling and male-row removal improved grain yield simulation for inbreds. For a set of 35 inbred-site-year simulations, the model simulated grain yield with satisfactory accuracy (RMSE 5 429 kg ha-1). Average grain yields were 4556 and 4721 kg ha-1 for the measured and simulated values, respectively. CERES- IM simulations suggest that the effect of male-row removal on grain yield is extremely sensitive to the precise date at which this operation is conducted. This would explain the inconsistent effect of male-row removal on female grain yields reported in the literature