<p>The results of previous studies generally show that organic production is more profitable than conventional production. However, as a source of these results, the trials are either of short duration or do not specifically examine the benefits during the transition period, suggesting that previous work may not have captured the full variability of crop net returns. The purpose of this study was to compare the net returns and risks of conventional, transition, and organic cropping systems using long-term crop budgets and stochastic simulations. Conventional crop rotations were represented by a corn / soybean rotation and a corn / soybean / wheat rotation. The organic crop rotation produced corn, soybean and wheat. Historical prices, crop budgets, and FINBIN data are used to develop the long-term crop budgets. The organic crop rotation included a three-year transition period. Ten-year enterprise budgets were created for each crop and rotation so that we could compare the net returns of the transition year of organic crop rotation and the year of organic production. This thesis summarizes the enterprise budget information for each crop in the conventional and organic cropping systems, and summarizes the information used for the simulation analysis. Using @ risk, differences in annual net returns to land between crop rotations were summarized. Results are as follows. First, the transition and organic cropping system was found to have higher net returns to land than the two conventional crop rotations under most of the simulation iterations. Second, the annual net returns during the transition period were relatively low. Third, the highest average annual net return was for organic corn.</p><div><br></div>

No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph.D.Agric.(Agronomy))-University of Pretoria, 2009. / Includes bibliographical references (leaves 75-87). Available in print and online.

Demand for potassium (K) increases with increasing soybean yield. Little research has been conducted on soybean response to K on coastal plain and piedmont soils of Virginia, especially in double-crop systems. Nineteen full-season and 14 double-crop soybean experiments were conducted in 2013 and 2014 in Virginia and northeastern North Carolina to determine full-season and double-crop soybean (with wheat straw remaining or removed) response to soil test K and K fertilizer application rates. Field moist, air dried, and oven dry soil test K extraction techniques were also compared to predict responsiveness of sites to K applications. Potassium fertilizer increased yield in five of 19 full-season experiments and one of 14 double-crop experiments. Full-season soybean yield plateaued at 88% relative yield and soil test K value of 38.8 mg K kg-1. Full-season plant K critical concentrations were 18.2 g K kg-1 for V5 and 24.6 g K kg-1 for R2. Although critical concentrations could not be determined for double-crop soybean, V5 and R2 concentrations ranged from 17.6 to 35.6 g K kg-1 or 13.2 to 28.1 K kg-1, respectively, most of which were within or above accepted sufficiency levels. Eight of 13 sites resulted in greater soil K concentrations when alternative soil drying methods were compared to air-dry methods. However, differences were not consistent and no single method was superior for these soils. More data is needed for double-crop soybean systems due to lack of response and lack of low soil test K sites in these experiments. / Master of Science

No description available.

Machine learning has been around for a long time, the applications range from a big variety of different subjects, everything from self driving cars to data mining. When a person takes a picture with its mobile phone it easily happens that the photo is a little bit crooked. It does also happen that people takes spontaneous photos with help of their phones, which can result in something irrelevant ending up in the corner of the image. This thesis combines machine learning with photo editing tools. It will explore the possibilities how machine learning can be used to automatically crop images in an aesthetically pleasing way and how machine learning can be used to create a portrait cropping tool. It will also go through how a straighten out function can be implemented with help of machine learning. At last, it is going to compare this tools with other software automatic cropping tools. / Maskinlärning har funnits en lång tid. Deras jobb varierar från flera olika ämnen. Allting från självkörande bilar till data mining. När en person tar en bild med en mobiltelefon händer det lätt att bilden är lite sned. Det händer också att en tar spontana bilder med sin mobil, vilket kan leda till att det kommer med något i kanten av bilden som inte bör vara där. Det här examensarbetet kombinerar maskinlärning med fotoredigeringsverktyg. Det kommer att utforska möjligheterna hur maskinlärning kan användas för att automatiskt beskära bilder estetsikt tilltalande samt hur maskinlärning kan användas för att skapa ett porträttbeskärningsverktyg. Det kommer även att gå igenom hur en räta-till-funktion kan bli implementerad med hjälp av maskinlärning. Till sist kommer det att jämföra dessa verktyg med andra programs automatiska beskärningsverktyg.

Photocopy of typescript. / Digitized by Kansas Correctional Industries

While many spring and winter wheat (Triticum aestivum) varieties have been evaluated for yield characteristics under Utah's conventional dryland cropping systems, little is known about these same varieties under new conservation tillage farming management techniques. Farmers are rapidly adopting various reduced tillage systems and need information regarding proper varieties, fertility practices, weed control , etc. A two year field study, in Box Elder County, Utah on a DeJarnet Gravelly silt loam (Loamy-skeletal, mixed, mesic, Calcic Pachic Haploxeroll) and on a Mendon silt loam (fine-silty, mixed, mesic, Calcic Pachic Argixeroll) examined total dry matter, grain yield, percent protein, kernel weight, kernel volume, and average bushel weight responses to four fertility treatments superimposed upon five spring wheat and four winter wheat varieties. Also compared were one spring wheat variety "Komar" and one winter wheat variety "Weston" in a conventional verses conservation tillage dryl and c ropping system. Soi 1 moisture and soi 1 temperature (20 em and 10 em, respectively bel ow the soi 1 surface) readings were compared between the conventional and conservation tillage planting systems. The conservation tillage plantings were done with an air-seeding tillage planter and the conventional plantings were done with standard deep-furrow drills. Dry granular fertilizer (27 -12-0-4 sulfur) was applied to both deepfurrow and conservation tillage plots with the air-seeder. Rates were 0, 168, 224, 280 kg/ha fertilizer material applied. Significant differences were obtained for all spring wheat varieties. Conservation-tilled "Komar" yielded significant yield increases ove r conventio na l- tilled "Komar". The opposite held true for "Weston" , with the conventional-tilled plots yielding a slightly significant increase in grain over conservation-tillage "Weston". No relative difference in soil water or soil temperature were observed in either variety through time. However, at certain growth stages the differences were clearly discernable. Very littl e significant differences were established amoung the winter wheat varieties. Because of heavy infestations of snowmold (Calonectria graminicola) on all winter wheat plots, the true potential yield characteristics of conservation verses conventional tillage remain unproven on these winter wheat varieties.