Corn and Sorghum Crop Management
The Nutrient Budget Tool is a resource for growers who are interested in adequately providing the correct amount of nutrients for their crops for the optimal yields. This tool allows growers to choose crop type and yield goals into a spreadsheet that will then output the needed fertilizer levels of N, P, K needed to meet projected yield goals. Soil test, irrigation water test, and manure nutrient test analysis results can also be input to calculate the overall results of a crop’s nutrient/fertilizer needs. This tool is designed to help promote soil testing and analysis and to help growers be more cost and nutrient efficient. We plan to expand the Nutrient Budget Tool in the future to incorporate soil salinity levels (EC) and pH to better service the nutrient budget users and provide greater information.
Nutrient Budget Tool
1. Choose the crop from the list of tabs at the bottom of the screen.
2. Fill in the “Plan Area” field in acres and “Yield Area” field in lbs/acre or tons/acre. Doing this will provide the needed N, P, and K requirements of the specified plan area.
3. Additional numbers from irrigation water analysis, soil analysis and fertilizer analysis from a plan area can be input to factor in to the overall needed requirements for N, P, and K in lbs/plan area.
When to harvest sorghum can be a difficult decision, due
to uneven maturity. Also, depending on the hybrid, the
stalks and leaves may still be green when the grain is ready
for harvest. Sorghum can be harvested when grain moisture
content is 18-23%, and harvest losses increase outside of this
moisture range. However, the grain can not be stored safely
over a long period of time above a moisture content of 12-
14%, so artificial drying is be necessary if harvesting high
moisture grain. Unfortunately, artificial drying facilities are
not available in Arizona, so grain should be harvested when
its moisture content is below 14%. Sorghum grain readily
absorbs moisture from the atmosphere, and grain moisture
content can change a few percentage points during the
day. Thus, check grain moisture before harvesting and stop
harvest before evening if moisture content increases above
suggested storage levels. Sorghum grain is brittle and more
easily cracked than the grain of wheat or barley, so care must
be taken in adjusting the combine
Suggested planting dates for grain sorghum are presented
in Table 1. Sorghum seed will germinate when the soil
temperature at seeding depth is 50°F, but germination and
growth will be slow and the seedlings will be susceptible
to disease. Faster germination and superior establishment
is obtained when the soil temperature is 60°F at 8 am for
more than 5 consecutive days. Sorghum may be planted in
the summer but grain yields are usually less than a spring
planting. The optimum date to plant in the summer is late
enough to avoid the heat during bloom but early enough to
avoid frost and poor drying conditions in the fall.