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The law describes several modes of lawn care like

type        max height, cm     cut height, cm   cuts per season      watering per season
parterre    5                  2 ~ 4            15 ~ 18              30
usual       10                 3 ~ 5            10 ~ 14              16
meadow      20                 3 ~ 5             2 ~ 5                0

Climate in south-eastern Ukraine is +30C all the summer, almost no rains.

Housing maintenance organizations usually have no any means to water the lawns, no money, no equipment for watering at all.

Last 50 years most lawns were kept in meadow mode, that means that they were cut about twice a year without any watering. The grass was very healthy, high and very diverse.

About 3 years ago all urban areas were switched to the "usual" mode ( tick and ragweed control ) In fact that means that the lawns are cut to zero several times per season without any watering.

As a result many lawns are yellow and dead for a long time and I see the gradual turf degradation.

You can see it at two photos made in the almost the same date ( end of April, start of March ) with three years interval:

enter image description here enter image description here

Also we have the mass death of the birches in the areas where the grass is regularly cut under them.

The officials say that they just follow the instructions to fight tick and ragweed and the grass will regrow later when we will have more rain.

I want to ask you to give your opinion about my understanding of the situation.

I described my understanding in several theses below. Please write me where I am right or wrong.

  1. The surface of the grass is the catalyst of the dew.
  2. The higher the grass the more dew it will produce
  3. The dew evaporates during the day decreasing the temperature and increasing the humidity
  4. The dew is daily precipitation that is important for all plants including the trees
  5. The death of the birches could be caused by the absence of the high grass and the absence of the dew.
  6. The turf degradation will continue if the grass is cut to zero several times per season without any watering.
  7. The turf degradation will cause the desertification in several years and eventually the death of most trees because level of evaporation will be higher and the amount of the dew will be zero.

( Also I will be very obliged if somebody could help me to contact the expert in the area of overgrazing and desertification.)

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  • $\begingroup$ A general remark that could help: frequent mowing not, as long as only the surface parts are affected, drought yes. Because of its evolutionary history (coevolution with herd animals, e.g. academic.oup.com/jpe/article/11/2/248/2738898) it is resistent against mowing/grazing. But the subsurface part, the rhizome needs some moisture. Drought will, depending on the type of grass, finish it off. $\endgroup$
    – user20217
    Jul 21 '20 at 15:35
  • $\begingroup$ The idea is like this: keeping the grass short means drought because dewfall will be close to zero. $\endgroup$
    – Aleksey
    Jul 22 '20 at 4:06
  • $\begingroup$ I got that :-) But grass is not a succulent, it lives by the roots. I would also take lack of rain, if there is such a lack, poisoned ground or overly use of herbicides, compaction of the ground or that the soil is inept for growing grass into consideration. $\endgroup$
    – user20217
    Jul 22 '20 at 9:56
  • $\begingroup$ I think you are right. I don't have scientific papers to back this, but any sustainable gardening magazine will tell you to mow less often and/or higher to prevent the grass from dying of drought. It has to do with a simple concept: evapotranspiration. With longer grass you prevent the soil from losing its water through evapotranspiration. Look for "sustainable lawn" for more info, and try to convince your local authority! Many towns have already turned to better practices. $\endgroup$ Jul 23 '20 at 7:30
  • $\begingroup$ Herb size is related to dewfall amount: "After crops were planted the number of dewfall-nights and the amount of dewfall per event rose quickly and eventually surpassed that on the lysimeters with grass. After harvest both parameters dropped well below the values on the grass lysimeters again." ( sciencedirect.com/science/article/pii/S0022169409004806 ) $\endgroup$
    – Aleksey
    Jul 23 '20 at 10:44

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