9ER8WMA5

3234

28 octobre 2020 12:35

12 avril 2021 16:18

Utah has a semi-arid climate, which is characterized by low precipitation, and calcareous soils generally low in soil organic matter. Dryland winter wheat is widely grown, significant acreage of which is certified organic. In the growing season, limited water decreases nutrient availability to the root surface and topsoil. Yields are severely constrained by lack of precipitation, and many dryland organic wheat growers do not apply fertilizers due to an inability to recoup costs. Compost enhances long-term improvement in soil quality, soil fertility and increases yield in low input environments. Understanding of compost carryover effects in dryland wheat systems is necessary for improved yields and quality that will allow adequate supply of nutrients for several years after initial application. A previous study on Utah calcareous soil showed evidence of soil benefits twenty-two years after a single application at 50 Mg ha-1 dry weight. A new experiment was initiated at the Blue Creek farm in 2011 to test the reproducibility of these findings on a less marginal soil type. Compost was applied at 0, 12, 25, and 50 Mg ha-1 plus a conventional fertilizer control in a wheat fallow rotation. Both phases of the rotation were present each year with a total of six replicates. Wheat yield was significantly increased three years after application at the 50 Mg ha-1 compost rate only. Conventional fertilizer increased grain protein. Mineralizable carbon (C), microbial biomass and phosphatase enzyme activity increased significantly at all compost rates, while available soil P increased at the 25 and 50 Mg ha-1 rates and total soil N at the 50 Mg ha rate-1. Subsoil moisture content increased linearly as moisture moved down the soil profile for both cropping seasons. Compost application rate of 50 Mg ha-1 had the highest amount of soil moisture. A lack of yield response to conventional fertilizer suggests improved soil health and or soil moisture was responsible for improved yields at the high compost rate.

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• AB - Utile à l'AB
• FREDO biologie et travail du sol
• FREDO fertilisation
• GEO Etats-Unis

2020

1 janvier 2020