Crop Rotation - Crop Development In rotation, sorghum takes the place of corn: so ideally it follows a legume (soybean, alfalfa, peas) and is followed by sugarbeet, tomato, potatoes and other crops. When wheat follows sorghum, a lack of Nitrogen can happen and some allelopathic effect is likely: therefore, wheat after sorghum is not suggested. Usually planting dates are later than for corn. Sorghum is a good alternative to corn where availability of water is not so abundant and general conditions are adverse. Nevertheless, the crop is demanding concerning temperature: minimum soil T for germination is 10°C and for growth is 16°C, optimum is 27-28°C. It is important for high yields that in July minimum be 21°C. Like any other crop, grain sorghum will respond to optimum growing conditions and proper timing of management inputs for maximum yields. Understanding how the grain sorghum plant develops is critical for understanding the crop’s needs and planning management inputs for maximum yields. As a Rule, Crop Rotation practices improve the performances of crops. Exploitation of soil fertility is improved, as different crops roots explore different layers of soil and use different nutrients. Structure of soils improves, because residues from crop roots stay at different depths and residues are also different. By varying crops in the same season, farmers can spread equipment demand throughout the season, reducing costs while increasing utilization. Management of weeds, pests, and diseases get easier because different crops have different pests. Sorghum, when in rotation with soybeans, wheat and sugar beet allows for better control of grasses weeds.
Tillage - Primary and secondary Grain sorghum needs a warm, moist soil well supplied with air and fine enough to provide good seed-soil contact for rapid germination. A number of different tillage and planting systems can be used to get these conditions. These systems may involve primary or secondary tillage or no tillage operations prior to planting. An ideal seedbed should accomplish these goals: - Control weeds - Conserve moisture - Preserve or improve tilth - Control wind and water erosion - Be suitable for planting and cultivating with available equipment. A good seed bed is important, because plant roots require water and oxygen from the soil roots pore space for sprouting. The right soil-air-water balance helps in limiting plant stress during drought periods and enables the plant to fully explore the soil profile for nutrients. Plants with a good soil-air-water balance are able to use water efficiently reducing watering needs and grow strong roots for good anchorage.
Planting - Uniformity is everything Producers should consider six agronomic drivers of seed placement accuracy at planting time. Depending on the type of seed and field conditions, certain drivers may have more or less importance: 1. Proper and accurate seed depth 2. Uniform and accurate seed depth throughout the field 3. Good soil-to-seed contact 4. Uniformly correct soil pressure all around the seed 5. Accurate seed population 6. Accurate in-row seed spacing Uniformity in sorghum emergence is an important factor for high yield crops. Producing a high yield crop starts with the right balance between healthy, productive plants and the plant’s ability to utilize available resources. Uniformity begins with a well-prepared seed bed. Plants that emerge uniformly and progress at the same rate of development throughout the growing season – also known as “photocopy plants,” – deliver improved yield potential. Two bad plants will not produce the same yield as one good plant. Uneven emergence introduces inefficiencies and adds competition within the stand. Larger, early emerging plants obtain a greater proportion of available resources (light, water, nutrients) than smaller, later-emerging plants.
Hoeing - Good hoeing can help IMPROVING WATER AVAILABILITY Interrow cultivation remains an option for control of weeds between bands of herbicides and for later emerging weeds. Heavy, high-residue cultivators can be effective even in no-till planted sorghum. They also can be used as backup where herbicides have performed poorly and where perennial weeds have not been controlled. Electronic guidance systems can increase cultivating speed and efficiency by reducing operator fatigue and cultivator blight. Read More
Crop Protection - Spraying Weed control in grain sorghum is best achieved with an integrated approach based on crop rotations and herbicides or tillage, which enhances the ability of sorghum to compete with weeds. Repeated tillage before sorghum planting can effectively control weeds, but it is not likely to provide always adequate protection from soil erosion by wind and water. Herbicides may substitute for some or all preplant tillage. Weed control is carried out both during the pre-planting, pre-emergence, and post emergence stages. Weed competition in grain sorghum can reduce yields, cause harvesting losses and increase the seed content of the soil seed bank. Even light weed infestations in the early growing season will reduce yields significantly. Grain sorghum seedlings grow slowly and are weak competitors to most weeds. Research data have shown that one pigweed plant per 3 foot of row left uncontrolled until sorghum reaches the three-leaf stage will reduce yields by 10 percent. Heavy infestations of grassy weeds may cause up to a 20 percent yield reduction in the first two weeks after sorghum germination. Late season weed infestations have less effect on produced yields, but reduce harvesting efficiency and may reduce harvested yields.
Harvesting Sorghum is ripe when grains moisture content is 14-15% which is ideal. Harvesting can be carried out at moisture of 20%. Grain sorghum can be harvested with a grain header (rigid cutterbar), preferably with guard extensions). Typically, guard extensions are attached to every other guard in standing grain sorghum. Guard extensions provide support to guide more heads into the header in order to reduce gathering loss. Excellent cutterbar maintenance and adjustments are vital. Cut just below the heads to minimize the stem and leaf entering