Zoysia, bermudagrass, water, and AI

I asked Google’s NotebookLM for some help with this one. I have grown enough grass and seen enough bermudagrass and zoysiagrass growing together in wet and dry conditions to have formed an understanding about these grasses. In short, bermudagrass outperforms zoysiagrass when these grasses are grown in a water deficit.¹ The larger the water deficit, and the longer the duration of the deficit, then the more obvious this difference will be.

I’ve written about this topic here before. See the “Related Posts” below for more about that. I still get asked about zoysia and water requirement, so I thought to remove my experience and observations, and to simply ask Google’s NotebookLM to summarize some research articles that consider bermudagrass, zoysia, and water.

I provided these five articles as sources.

• Sifers and Beard, 1997: Bermudagrasses superior in dehydration avoidance and drought resistance when compared to zoysiagrasses
• Zhang et al., 2019: Drought responses of above-ground and below-ground characteristics in warm-season turfgrass
• Culpepper et al., 2020: Comparison of four warm-season turfgrass species to natural rainfall or supplemental irrigation in a semiarid climate
• Katuwal et al., 2022: Multilocational screening identifies new drought-tolerant, warm-season turfgrasses
• Schiavon et al., 2025: Irrigation frequency requirements for sufficient warm-season species quality in Florida

I asked for an audio overview on that topic, which you can listen to here.

• Listen to AI-generated audio overview

I also wanted a short textual summary, so in the chat I provided this prompt:

Can you provide a one sentence summary for each of the five articles, on the topic of bermudagrass vs zoysiagrass water requirement? Then provide a 1 paragraph synthesis of the topic based on these five sources.

This was the response from NotebookLM:

Here is a one-sentence summary for each of the five articles regarding bermudagrass versus zoysiagrass water requirements:

• Schiavon et al. (2025) found that bermudagrass generally maintained higher turfgrass quality with less frequent irrigation compared to zoysiagrass in a Florida study evaluating different irrigation regimes.
• Beard and Sifers (1997) determined that bermudagrass possesses superior dehydration avoidance and drought resistance compared to zoysiagrass due to its greater root depth and lower evapotranspiration.
• Culpepper et al. (2020) concluded that bermudagrass maintained better quality with natural rainfall alone in a semiarid climate, while zoysiagrass required supplemental irrigation for acceptable quality.
• Katuwal et al. (2022) indicated that zoysiagrass generally exhibited a greater decline in green cover and photosynthetic potential under drought conditions compared to bermudagrass in a multilocational screening.
• Zhang et al. (2018) demonstrated that bermudagrass endured drought for a longer period with less green cover loss and had a more extensive root system at deeper depths than zoysiagrass.

Synthesizing these findings, the research consistently indicates that bermudagrass generally requires less irrigation water than zoysiagrass to maintain acceptable turfgrass quality. This difference is largely attributed to bermudagrass’s superior drought resistance mechanisms, including a more extensive and deeper root system that allows for greater access to soil moisture, as well as a lower evapotranspiration rate in some instances. In contrast, zoysiagrass tends to have shallower root systems and often exhibits greater quality decline under water-limited conditions, necessitating more frequent or higher volumes of irrigation to sustain comparable quality to bermudagrass.