California Agriculture

In an increasingly unstable climate, it is critical to optimize water needed for crop irrigation to secure food production and livelihoods while reducing environmental impacts. Here, we focus on water use for almonds — a crop that occupies roughly 20% of the irrigated agricultural land in California and has long been the focus of scrutiny. Regenerative agriculture, a term used to describe system designs that increase soil health, biodiversity, resilience to climate, and profitability while reducing greenhouse gas emissions, water use, and pollution, offers a potential way forward. We used eddy covariance, micrometeorological, and soil moisture measurements from 2022 and 2023 to quantify the evapotranspiration of California almond orchards under different soil and plant management practices and produce comprehensive estimates of the water footprint of different management systems. In five almond orchards, we find that there is little difference between evapotranspiration at regenerative and conventional sites in winter months, and that regenerative sites have similar or slightly lower evapotranspiration during the growing season. Orchards with cover crops had higher infiltration rates of winter precipitation than those without; however, soil moisture did not differ between management types. This case study demonstrates that regenerative management in almond orchards leads to improvements in soil moisture retention without guaranteeing increased evapotranspiration.

Nitrogen fertilizers in irrigated agriculture improve cropland productivity, but contribute to groundwater contamination, air pollution, and greenhouse gas emissions. While California has implemented agricultural water quality regulations since the 1980s, targeted efforts to address nitrate contamination through nitrogen application reporting and management have been emphasized more recently under the Irrigated Lands Regulatory Program. This study uses a unique, field-level dataset from the Kings River Water Quality Coalition in California’s Central Valley to examine nitrogen management practices, including common combinations of practices (bundling), across crop types. The analysis draws on four years of data from Irrigation and Nutrient Management Plans and details nitrogen application and management strategies. The results show that in 80% of fields across crops, between 50 and 300 pounds per acre (lbs/acre) of nitrogen is applied. Crop-level nitrogen applied minus nitrogen removed (A-R) values show substantial variation, with walnuts showing a nitrogen surplus (+65.5 lbs/acre) and alfalfa a significant deficit (−424.5 lbs/acre). Many growers adopt multiple practices, with 26% of fields utilizing six practices and 24% using five. Such bundling may provide growers with more flexibility in managing nitrogen applications. Further research is needed to evaluate the effect of various nitrogen management practices on fertilizer use and water quality effects.

California processing tomato growers must adapt their irrigation management practices to cope with frequent droughts and increasingly limited groundwater supplies. Processing tomatoes’ water stress tolerance provides a water savings opportunity through deficit irrigation. However, it is important to initiate deficit irrigation at key growth stages to maintain yields. We conducted a deficit irrigation experiment over three years using a randomized block design with four treatments in three commercially operated fields in Fresno County. A tapered deficit treatment was applied, where the amount of water deficit was increased partway through the deficit period to ease the crop into higher water stress while further reducing irrigation. In all three seasons, there were no differences between treatments in yield, with some seasons having an improvement in Brix with the higher deficit treatments. This was achieved with up to a 29% reduction in irrigation compared to the grower’s standard practice. The results of this study suggest that tapered deficit irrigation can be a viable option for optimizing water savings in processing tomato systems.

California’s agricultural employers hired an average 414,000 workers between 2018 and 2023 and reported an average 886,000 unique farmworkers each year, a ratio of 2.1 workers for each average or full-time equivalent (FTE) job. The ratio of two workers for each FTE job is stable, but a rising share of workers are brought to farms by nonfarm crop support firms, including farm labor contractors (FLCs). Farmers outsource seasonal and specialized tasks to crop support firms to save money by paying for labor and other services when they are needed. FLCs account for two-thirds of average crop support employment, which highlights the challenge of regulating the intermediaries whose average employment is about the same as for workers hired directly by crop farmers.

Study findings from Southern California avocado orchards help growers save water and money.

UC scientists report that wealth, pollution and population density affect how coyotes move and adapt to urban areas.

Plantar árboles inmediatamente tras un incendio forestal es crucial para las comunidades, ecosistemas y objetivos sobre carbono.

4-H animal education programs and poultry competitions evolve with the ongoing bird flu outbreak.

The Spanish-language podcast goes behind the scenes with UC ANR’s Latino staff and academics to provide science-based information to audiences across California and beyond.