Development of a Sustainable Cropping System for Industrial Hemp Production by Limited Resource Farmers

View the project final report

Commodities

• Agronomic: peas (field, cowpeas), hemp
• Fruits: melons
• Vegetables: cucurbits, okra

Practices

• Crop Production: crop improvement and selection, intercropping, pollination

Industrial hemp (Cannabis sativa (L.)) is one of the oldest cultivated plants in the world grown for fiber, oilseed, and pharmaceuticals. After ≥80 years, hemp has been legalized to be grown again in the U.S; however, knowledge needed to grow hemp is limited. Research must now be initiated to ensure farmers are able to make informed decisions and avoid economic losses. The proposed experiments were developed with input from three studies by the PIs. (1). In a 2019 survey, 85% of organic farmers in NC were interested in growing hemp on their farms. Among them, 93% would grow hemp because there is a market, >84% if it fits into their current rotation, has low insect and disease pressure and diversify their farm. (2). We identified cowpea cultivars highly attractive to pollinators that increased crop yield in a vegetable intercropping system. In addition to supporting pollinator activity, cowpea fixes atmospheric nitrogen. This process can contribute a significant amount of N (>45-175lbs N/ha) to the subsequent crop thus improving soil health. (3). An ongoing soil fertility trial indicates hemp requires approximately 50-100lbs N/ha which is within the range reported for cowpea. With the soaring fertilizer prices alternative sources of soil fertility enhancers are going to be needed by farmers. For example, they can use legume such as cowpea, grown either as an intercrop or in rotation with hemp to provide the required N-level to produce higher yields. Crop rotation and intercropping are important cultural practices in crop production and pest management based on the principle of reducing pests and improving soil health. In the proposed system, pollinators would be attracted to cowpea for its nectar and hemp for pollen thus providing important ecosystem services, a component of productivity and as a forage resource. Pollinators as a whole contribute $24 billion and honey bees $15 billion to the U.S economy. However, its role in agricultural enterprise has recently been compromised by the decreasing bee populations. Since 2006, U.S beekeepers have seen >40% decline in honey bee colonies; according to NC State Beekeepers Association, there was >50% loss in 2018, impacting the state's $84 billion agriculture industry. As a countermeasure, one strategy has been to increase abundance of bee forage resources on farmlands. We propose to achieve this through intercropping and rotation using cowpea highly attractive to pollinators. The primary goal of this project is to develop a sustainable research-based strategy and communicate information on pests, pollinator activity, soil health in a cropping system perspective that will help farmers make informed decisions about hemp production. To attain this goal, we propose four specific objectives: a) identify hempseed cultivars suitable to grow in NC-reduced pests, pollinator-attractive and high yielding; b) evaluate integration of hemp into two cropping systems- crop rotation and intercropping; c) evaluate soil health indicators with respect to biological nutrient cycling and microbial community; (d) assess system profitability from best production practices derived from a-c. Overall, the proposed project will enhance hemp production through management strategies that are sustainable and cost-efficient.

Objective 1. Screen 10 to 15 industrial hemp seed cultivars to identify cultivars with high yields, reduced pests incidence suitable to grow in North Carolina

Objective 2. Evaluate the effect of integrating five agronomically desirable hemp seed cultivars (from objective 1) in an intercropping system that includes Hemp+Cowpea+Pollinator-Dependent-Crop. The pollinator-dependent-crop may include cucurbits (such as water melon, watermelon or squash) or okra.

Objective 3. Measure biological soil health dynamics with respect to microbial nutrient cycling and microbial communities in each of the two systems described in objectives 2 and 4.

Objective 4. Assess system profitability from best production practices used in objective 2 and evaluate the effect of crop rotation at collaborative farmer-managed farm and at NCAT research plot.