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Core Ideas Organic amendments are promoted as sustainable alternatives to synthetic fertilizer. Crop yield increased by an average of 43% in the first season after organic soil amendment. Yield benefit from organic amendments was greater in leafy crops than root crops. Poultry manure was commonly used and provided the greatest agronomic benefit. Yield benefit of organic amendment was lower in arid regions with poor soil quality. Organic soil amendments are increasingly promoted as a sustainable alternative to synthetic fertilizers and as a tool for building soil quality through improved chemical, physical, and biological properties. However, short‐term yield response to organic amendments is highly variable. A meta‐analysis of 53 studies was conducted to (i) develop a global estimate of first‐season crop yield response to organic amendments, and (ii) determine the effect of crop type, amendment characteristics, soil properties, cultural practices, and climate on the magnitude of this yield response. Yield response ratios were calculated (organic amendment yield compared to a non‐fertilized control) and differences among groups were determined using 95% bootstrap confidence intervals (CI). Across all studies, crop yield increased 43±7% (95% CI) in the first‐season after an organic amendment. Yield response was greatest for leafy crops (71±26% increase) and lowest for root/tuber/bulb crops (29±10% increase). Poultry manure/compost was the most commonly used amendment and provided a yield increase of 76±21%. In contrast, plant‐based amendments increased yield by only 27±9%. Amendment application rate alone was not an effective predictor of yield response, and there were not enough studies available to explore the possible interaction between amendment type and rate. Yield benefits of organic amendments were muted in soils with high organic matter and in arid climates. These results help identify options for maximizing the agronomic value of organic amendments, and suggest research is needed to improve agronomic efficiency of amendments in arid regions with poor soil quality.

Core Ideas Infiltration rate, but also irrigation demand, was highest in compost raised beds. Compost in raised beds reduced the need for mineral fertilization across two seasons. Weed abundance in raised beds increased when top soil was mixed with compost. Crop yield was usually highest in raised beds, regardless of media composition. Raised beds are commonly used in urban agriculture, but crop production benefits have not been well studied. The objective of this 2‐yr field experiment in Illinois was to determine the effects of urban production system (direct soil, raised bed with compost, or raised bed with mixed compost and soil) and fertilizer source on growing media properties, weed abundance, and vegetable crop yield. Due to the presence of compost, raised bed media had higher pH, organic matter, and nutrient concentrations. Water infiltration rate was 20× higher in raised beds with compost only compared to soil. Mixing soil with compost in raised beds reduced nutrient concentrations and water infiltration rate compared to compost‐only beds. Compost‐only raised beds required more irrigation than direct soil due to lower bulk density and greater porosity, but mixing soil with compost in raised beds reduced irrigation demand by 32% in year two. Compared to direct soil, compost‐only raised beds reduced grass and broadleaf weed abundance by as much as 97 and 93%, respectively. Radish (Raphanus sativus L.), kale (Brassica oleracea L.), and cilantro (Coriandrum sativum L.) yields were highest in raised beds, regardless of growing media composition, whereas garlic (Allium sativum L.) and pepper (Capsicum annuum L.) yields were less influenced by production system. We recommend raised beds with a mix of compost and soil for vegetable production in urban agriculture.