Producers are frequently most interested in economic comparisons of various cropping systems. We compared continuous corn (Zea mays L.) and continuous soybean [Glycine max (L.) Merr.] with 2-, 3-, and 5-year rotations, the latter two including wheat (Triticum aestivum L.) and alfalfa (Medicago sativa L.), using either chisel plow or no-tillage practices. Crop yield and returns to land and manag...

Abstract In areas with a pronounced relief, water erosion causes great harm to agriculture and other sectors of the national economy. It leads destruction soil cover, reduction in area arable land, decrease fertility, removal products into floodplains, siltation ponds rivers road network. The scientific goal was identify influence main natural factors (snow reserves, freezing moisture) on forma...

Plow pan is one of the main obstacles to high production agricultural plants in Chongqing, China. As a minimal tilling method, subsoiling can break plow and help growth plants. There are two methods: vibrating (VS) traditional (TS). A soil model with upland field features Chongqing was established for DEM-based simulation. The simulation validated by experiments, items looseness, coefficient di...

In this paper we describe an Interior Point Method (IPM) to solve large scale NonLinear Programming (NLP) problems, tailored to the solution of a specialized Optimal Power Plow (OPF) formulation that uses bus voltages in rectangular coordinates. The distinctive feature of this OPF formulation is that the objective function and constraints are quadratic functions, and such quadratic properties a...

much has been learned in recent years about the factors affecting reflection of sunlight by soils, the influence Knowledge of how surface roughness influences the reflectance of of w on albedo of rough soil surfaces is still poorly sunlight from cultivated soils is useful in various applications, such as estimating albedo values used as inputs to soil temperature models understood (Cresswell et...

Preliminary reports of part of this work have appeared in abstract form in Clin. Res. 26: 503A, 1978, and in Blood. 54(Suppl. 1): 241a, 1979. Dr. Gerrard and Dr. Plow are established Investigators of the American Heart Association. Reprint requests should be addressed to Dr. Gerrard, Manitoba Institute of Cell Biology, Manitoba R3E OV9, Canada. Received for publication 15 November 1979 and in r...