SUSTAINABLE FARMING PRACTICES, CROP MANAGEMENT AND SORGHUM IMPROVEMENT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1022585
• Project Start Date: Jul 1, 2020
• Project End Date: Jun 30, 2025
• Program Code: [(N/A)]- (N/A)

Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523

Performing Department
Administration

Non Technical Summary
Farmers in Southeastern Colorado, which is in the heart of the historic dust bowl, struggle with balancing conservation of resources, especially land, water, and inputs, while remaining sustainable and economically viable. Collectively, we must remember that a key component of being sustainable is being profitable.Considering these challenges, those farming practices which promote good stewardship of land, water and inputs and are sustainable, need to be studied and extended to the local growers.Components of sustainable farming practices may include adapted hybrid selection, such as sorghum (choosing the best adapted sorghum hybrid is one of the least expensive and yet potentially one of the most cost-effective decisions growers make); lowering input cost, such as strip till P placement compared to planter P placement (strip till allows the placement of lower cost anhydrous N fertilizer and deeper, root-capturing placement of phosphate fertilizer while fracturing shallow tillage pans directly below where the crop seeds will be planted with less disruption of the soil-conserving crop residue than conventional tillage); a four-year rotation (a winter crop, followed by a summer crop, followed by another summer crop, followed by fallow) may suppress weeds for less weed control cost than a three-year rotation (a winter crop, followed by a summer crop, followed by fallow); soil conservation, narrow-row air seeding of sorghum (narrow-row seeding is drilling the seed rows instead of conventional row crop arrangement for quicker row crop canopy), may conserve soil with narrowly spaced plants and soil moisture by shading competitive weeds; and alternating cover crops in dryland fallow strips between strips of row crops may promote soil health and abate soil erosion.

Animal Health Component

90%

Research Effort Categories

Basic

(N/A)

Applied

90%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0199	1060	35%
102	1520	1080	15%
102	0199	3100	35%
102	5210	3100	15%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
1520 - Grain sorghum; 0199 - Soil and land, general; 5210 - Fertilizers;

Field Of Science
1060 - Biology (whole systems); 1080 - Genetics; 3100 - Management;

Keywords

sorghum

crop rotation

p placement

cover crops

narrow row

strip-till

hybrid performance

sustainable practices

soil conservation

Goals / Objectives
Goal: Evaluate sustainable production practices for Southeastern Colorado to counteract soil erosion and scarce and more costly inputs.Objectives:Evaluate alternating row crop and fallow cover crop strips for yield, soil erosion abatement, and variable net income.Provide grain and forage sorghum hybrid selection tables based on maturation and adaptation to our local environments to aid sorghum growers in their planting decisions.Determine the yield and income of narrow row air seeder compared to conventional row vacuum planter for dryland grain sorghum production.Compare strip-till and planter applied P placement for emergence, plant stands, canopy cover, grain yield, and variable cost and income of grain sorghum.Assess a four-year (Wheat-Corn-Millet-Fallow) and a three-year (Wheat-Sorghum-Fallow) rotation for weed suppression, yield, and variable cost and income.

Project Methods
1) Cover crops planted in fallow will be followed by corn or grain sorghumin a dryland study with a minimum of two farm-scale replications in randomized treatments. Spring cover crops will be planted in corn and sorghum stalks in March and terminated in July.Cover crops will be mixes of grasses, broadleaves, and legumes.We will record cost of cover crop seed and planting, cover crop forage yields, cover crop water use, N analyses of cover crop forage, corn and sorghum stands, sorghum tiller counts, test weights, grain yields and variable net incomes of corn and sorghum following cover crops and conventional fallow.2) Grain and forage sorghum hybrids will be tested in dryland performance trials with a minimum of three replications in randomized complete block designs (RCBD). We will record plant density, mid-flowering date, plant height, lodging, maturity, yield, test weight (for grain sorghum), stalk sugar (for forage sorghum) and other pertinent information.3) Grain sorghum will be planted with a narrow-row air seederand comparedwith a conventional-row vacuum planter in a dryland study with a minimum of two farm-scale replications. We will record plant density, canopy cover, mid-flowering date, plant height, maturity, grain yield, test weight, harvest tiller count, and variable cost and income.4) Strip-till P placement with chisel shanks, planter P placement in the seedrow at planting, and the combination of strip-till P/planter P placementswill be compared in a dryland grain sorghum study with a minimum of two farm-scale replications.We will record plant density, canopy cover, mid-flowering date, plant height, maturity, grain yield, test weight, harvest tiller count, and variable cost and income.5) A four-year (Wheat-Corn-Millet-Fallow) rotation and a three-year (Wheat-Sorghum-Fallow) rotation will be comparedwith a minimum of two replications of large strips with all phases of each rotation present each year. We will record weed suppression and cost of weed control, yield, and variable cost and income of the rotations.

Progress 07/01/20 to 09/30/20

Outputs
Target Audience:Growers in the Southern High Plains and other arid drought-prone areas where wind erosion is a concern. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Presentations at grower meetings: Plainsman Agri-Search Foundation annual meeting, Plainsman Research Center Advisory Committee annual meeting, Pesticide Applicators Continuing Education seminar; technical reports: Plainsman Research Center, Research Reports, Sorghum Hybrid Performance Trials in Eastern Colorado; and web-published reports (all technical reports are printed and web-published). What do you plan to do during the next reporting period to accomplish the goals?Compare a four-year rotation (Wheat-Corn-Millet-Fallow) for weed suppression, grain production and income to a conventional three-year rotation (Wheat-Sorghum-Fallow).

Impacts
What was accomplished under these goals? Currently there are two major planting systems for seeding grain sorghum in our area: air seeder with narrow rows (0.25m spacings) and vacuum planter with conventional rows (0.76m spacings). There are potential advantages for both systems. The advantages for the air seeder are that it increases planted acres and the narrow rows may suppress weeds. The advantages for the vacuum planter are precise placement of seeds and the ability to cultivate between rows and harvest lodged plants. We conducted this study because growers inquired about possible yield advantages between the planting systems. We used a wheat stubble site with a thick mat of wheat residue for this dryland grain sorghum planting study. We compared a 36-row air seeder with 0.25m row spacings and an eight-row vacuum planter with 0.76m row spacings. We planted at 13,800 seeds/ha for the vacuum planter and we planted around 24,300 seeds/ha for the air seeder. In 2019, the dryland grain sorghum planted with the vacuum planter on 0.76m row spacing produced 583 kg/ha more than the air seeder with 0.25m row spacing. The 0.76m row vacuum planter also had 10 g/L higher test weight than the 0.25m row air seeder. There are two plausible reasons that contributed to the higher yield of the vacuum planter compared to the air seeder. First, we notice that the stand of the air seeder had some gaps down planted rows; whereas, the vacuum planter had more uniform stands. The reason there were planting gaps in the air seeder treatment was because it required a rather long planting distance to properly distribute the seed, particularly for low seeding rates. Even though these were large field size plots, uniform seed distribution was difficult to achieve, particularly at the beginning of the plots. This year it was not an issue for the vacuum planter with its row cleaners and precision seed plates to achieve uniform stands. The second reason the vacuum planter produced higher yields than the air seeder was because of weeds. The gaps from nonuniform seed distribution allowed weeds to flourish and cultivation was not an option for the air seeder with its narrow seed rows. Two years earlier from this study we reported the opposite results: the air seeder with 0.25m row spacings produced 1336 kg/ha higher yield and 19 g/L higher test weight than the vacuum planter with 0.76m row spacings. Like in 2019, we notice large gaps down planted rows, but this time the vacuum planter had the plant gaps and the air seeder had uniform stands. Often, the conventional row vacuum planter was not able to achieve good seed-to-soil contact because of the thick wheat residue mat, which created planting gaps. We installed row cleaners on the vacuum planter that alleviated this problem for subsequent plantings of this study. There were many weeds in the planting gaps of the vacuum planter, but we were able to cultivate some of the weeds between the rows. However, the weeds down the rows remained in the planting gaps, which lowered yields. Also, we noted that the narrow rows of the air seeder significantly suppressed weeds, so much so, that we recommend it for weed suppression. In 2020, the narrow row air seeder and conventional row vacuum planter comparison study was not harvested in 2020 due to dry conditions. Dry planting conditions caused delayed seedling emergence for both the air seeder and vacuum planter systems. Nonetheless, after germinating rains, both planting systems produced uniform plant stands. At maturity, we observed that there were no harvestable heads for the air seeder, whereas the vacuum planter had many harvestable heads. The higher plant population and the narrow 0.25m rows of the air seeder undoubtedly increased vegetative water use compared to the lower population, 0.76m row vacuum planter. The vacuum planter with less water use for vegetative growth had more water left for grain filling than the air seeder. Under dry conditions with uniform stands, the 0.76m row vacuum planter produced more mature heads than the 0.25m row air seeder. Impact: For the above average precipitation years of this study, uniform plant stands were the key to achieving high yields for both the conventional row vacuum planter and narrow row air seeder systems. When the planters had poor stands and plant gaps, they had low yields, and when the planters had uniform stands, they had high yields. It is critical that growers using either planting system to properly adjust their planters for the planting conditions to achieve uniform plant stands. For above average precipitation years, growers using narrow row air seeders will have better weed suppression (reduced herbicide use and cost) and superior stalk residue (reduced soil erosion) than conventional row vacuum planters. For below average precipitation years with uniform stands, conventional row vacuum planters produce more harvestable heads (greater production and income) than narrow row air seeders.

Publications

• Type: Other Status: Published Year Published: 2020 Citation: Larson, K.J., et al. 2020. 2019 Sorghum hybrid performance trials in Eastern Colorado. Technical Report TR20-6. AES, College of Ag. Sciences, Extension, Dept. of Soil and Crop Sciences, CSU. 17p.
• Type: Other Status: Published Year Published: 2020 Citation: Larson, K.J., et al. 2020. Plainsman Research Center 2019 research reports. Technical Report TR20-7. AES, College of Ag. Sciences, Extension, PRC, Dept. of Soil and Crop Sciences, CSU. 95p.