Various agronomic technologies are described, including a computer-implemented method for forecasting crop yield and an agronomic web portal including determining an expected yield at a first time, determining a growth function representing how the expected crop yield changes over time and based at least in part on an intrinsic yield function and the growth function, determining an expected yield at a second time, wherein the second time is later than the first time.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A computer-implemented method for forecasting crop yield, the method comprising: determining an expected yield at a first time; determining a growth function representing how the expected crop yield changes over time; and based at least in part on an intrinsic yield function and the growth function, determining an expected yield at a second time, wherein the second time is later than the first time. 2. The computer-implemented method of claim 1, wherein the growth function is determined based on a plurality of parameters, the respective parameters each representing one or more environmental factors or one or more cultural farming practices. 3. The computer-implemented method of claim 2, wherein the one or more environmental factors comprises at least one of weather conditions, soil conditions, or terrain, and wherein the one or more cultural farming practices are actions taken with respect to a field growing a crop for which the expected yield at the second time is determined, the cultural farming practices comprising at least one of soil disturbance, soil amendment, fertilizer application, fertilizer characteristics, pesticide application, pesticide characteristics, crop rotation, planting depth, planting density of a the crop, planting density of an alternate crop rotated with the crop, crop characteristics, crop residue management, weed management, tillage, canopy management, protective seed treatment, seed characteristics, characteristics of equipment used to manage the first crop, and a path or a speed of equipment traveling over the field growing the crop. 4. The computer-implemented method of claim 1, wherein the intrinsic yield function corresponds to a crop yield under assumed conditions. 5. The computer-implemented method of claim 1, wherein the intrinsic yield function is a probability distribution function. 6. The computer-implemented method of claim 5, wherein the intrinsic yield function represents a maximum yield determined at least in part from data reflecting a variety of environmental factors and cultural farming practices for a crop variety for which the expected yield at the second time is determined. 7. The computer-implemented method of claim 1, wherein the growth function is a probability distribution function. 8. The computer-implemented method of claim 7, wherein determining the growth function comprises performing a simulation to generate a value for each of a plurality of field locations at each of a plurality of times. 9. The computer-implemented method of claim 8, wherein the value of the growth function at a particular field location and time is correlated to the value of the growth function at another field location or time. 10. The computer-implemented method of claim 1, further comprising receiving identification marker data, the identification marker data associated with at least one of applied seed, applied pesticide, or applied fertilizer, and wherein the growth function is based at least in part on the received identification marker data. 11. The computer-implemented method of claim 10, wherein the identification marker data indicates a detection of a tracking substance. 12. The computer-implemented method of claim 11, wherein the tracking substance is a substance that is present in seeds, pesticide, fertilizer, or other applied material in a concentration or a combination not naturally found in an area where the tracking substance is detected. 13. The computer-implemented method of claim 11, wherein tracking substance is an inert sub stance. 14. One or more computer-readable storage media storing computer-executable instructions that, when executed, perform a method for forecasting crop yield, the method comprising: receiving at least one of environmental data or cultural farming practice data for one or more fields growing a crop of a crop type; and constructing a location-specific growth function that estimates a change in an expected crop yield over time for the one or more fields growing the crop of the crop type, the growth function based on the at least one of environmental data or cultural farming practice data. 15. The computer-readable storage media of claim 14, wherein constructing the location-specific growth function comprises: fitting yield data to a yield distribution function, wherein the yield data is a function of time and geospatial location and represents empirical data for the one or more fields growing the crop of the crop type; based at least in part on the yield distribution function, calculating an average yield and a full-width half maximum (FWHM) of the yield distribution function with respect to each of a plurality of environmental factors or cultural farming practices corresponding to the environmental data or cultural farming practices data; and determining a plurality of calibration constants for the yield distribution function based at least in part on the calculating. 16. The computer-readable storage media of claim 14, wherein constructing the location-specific growth function further comprises, based at least in part on the plurality of calibration constants, constructing a hypersurface. 17. The computer-readable storage media of claim 14, wherein the method further comprises determining an expected yield at a time later than a current time based at least in part on an intrinsic yield function representing crop yield for the crop type and the location-specific growth function. 18. The computer-readable storage media of claim 17, wherein the method further comprises: analyzing, for the crop type, crop yield data for a plurality of fields; and based at least in part on the analyzing, determining the statistical intrinsic yield function. 19. One or more computer-readable storage media storing computer-executable instructions that, when executed, perform a method for forecasting crop yield, the method comprising: generating a yield trajectory for each of a plurality of locations in a field or group of fields, the respective yield trajectories representing an expected yield as a function of time for a set of environmental factors and cultural farming practices, the respective yield trajectories generated by: determining an intrinsic yield function for the location, the intrinsic yield function representing a yield determined from a set of empirical observations; determining a growth function having values for the location at each of a plurality of time steps, the growth function based at least in part on a plurality of parameters reflecting at least some of the environmental factors and cultural farming practices; and for each of the plurality of time steps after an initial time step, calculating an expected yield based at least in part on an expected yield of the previous time step, the intrinsic yield function, and the growth function; and combining the yield trajectories for the plurality of locations in the field or group of field to determine an expected yield for a growing season. 20. The computer-readable storage media of claim 19, wherein for the respective yield trajectories, a maximum yield is determined by performing a simulation.