Tomato farming tips - tackling challenges with manure

By Blake Jackson

Manure offers a bounty of nutrients for plants, including nitrogen, phosphorus, potassium, and micronutrients. However, for tomatoes, it's a double-edged sword.

Tomatoes struggle to regulate their nitrogen intake. Too early on leads to excessive foliage, small fruit, and quality issues. This also creates an unrealistic demand for potassium, further impacting fruit quality. Conversely, nitrogen deficiency during fruit set reduces yields.

Experienced growers address this by starting with a moderate amount of nitrogen at planting and monitoring plant tissue every other week to adjust further nutrient needs.

Manure presents two challenges: unpredictable nitrogen release and spreading accuracy. Manure nitrogen comes in two forms: readily available ammonia and slow-release organic nitrogen. This makes it difficult to control the flow of nitrogen to the plant. Additionally, manure spreaders often lack the precision needed for tomato production.

So, how can vegetable farmers leverage manure's benefits?

• Light application months before planting: Allows ammonia to volatilize (evaporate) and reduces the risk of excessive nitrogen impacting young plants.
• Supplement with irrigation: Use tissue tests to determine additional nutrient needs during fruit set, as manure alone might not provide sufficient nitrogen.
• Heavy manure application in rotation years: Build up soil nutrients in other crops within the rotation to minimize manure use for tomatoes. Pre-plant nitrogen should be minimal if manure was applied in previous years.

Another concern with manure is the presence of harmful bacteria like E. coli and salmonella. Federal regulations prohibit applying raw manure directly to growing vegetables, including manure teas.

Composting offers a safer alternative. Properly composted manure, where temperatures reach 131 degrees for 15 days, eliminates these pathogens. However, records documenting the composting process are required. Unlike raw manure, properly composted manure can be applied to harvest if these records are available.

The key takeaway: moderation is crucial. Excessive nitrogen application, even from seemingly safe sources like compost, can lead to detrimental effects on tomato plants. Utilize manure strategically in your crop rotation and rely on tissue testing for informed nitrogen management throughout the season.

Photo Credit: gettyimages-bastetamn