When the lawn turns yellow, on which a lot of effort has been expended, it is useless to shrug hands. Urgent need to save the green carpet, on which yellow spots appeared, to create favorable conditions for the grass. From personal experience I know, the sooner the cause of yellowing is identified, the more chances there are to do without digging the lawn.
Causes of Yellowing Grass
There are many factors, from poor soil preparation to adverse weather, year after year is not necessary. Grass can change color in summer and autumn. Sometimes the lawn begins to dry in the spring when everything is growing.
Soil condition
When the lawn turned yellow after winter, the first thing you need to check the level of groundwater. The reason for flooding is the layout of neighboring areas, the movement of storm drains is disrupted.
Another possible cause of yellowing of the grass is inappropriate soil acidity.
Bluegrass grasses do not like excess alkaline elements. Cereals suffer when the earth is too acidic. Ryegrass grows equally well everywhere, but it has a different misfortune - hummocks form, which are also able to turn yellow when there is insufficient nitrogen.
By the way, the acidity of the soil rises when the lawn is often walked. The earth is compacted, natural channels are clogged, water accumulates in small puddles.
When buying seeds, you should immediately determine the expected load. It’s one thing to walk on the lawn with a lawn mower; it’s another to play football. Each grass has its own purpose.
I remember how happy we were when we bought a mixture for the ground grass. In the picture everything looked beautiful. The shoots were friendly. But when the holidays began for the children, our lawn began to look pathetic - it looked like the skin of an abandoned dog.
Many or few fertilizers
Another reason is a lack of nitrogen and iron. Ammonia mixtures fertilize grass only until mid-summer. When ammofosku or urea is introduced later, the grass actively grows and does not withstand frosts. Excess nitrogen causes serious consequences. Once the lawn turned completely yellow after winter. All young growth has died.
Red filament is a characteristic sign of a lack of nitrogenous feeding. Usually, symptoms of damage are noticeable in the fall. Small tan marks appear on the lawn - the thinned grass dries, breaks off. The lawn becomes like a carpet burnt out from the sun.
Iron sulfate is a good prevention of fungal infections, creeping of moss. When summers are rainy and warm, spores develop faster. From frequent fogs, prolonged rains, moss appears.
In autumn, it is advisable to add trace elements every year. When the soil becomes thinner, the grass stand worsens, new growth points do not form, bushes do not grow in breadth. The roots begin to stifle the undergrowth. There are bald spots.
Lawn grass needs to be fed no less than the rest of the garden crops. Especially affected are the so-called sports lawns - curly dense grass springing underfoot. They require careful care, they need complex fertilizers.
Restless winter
In winter, the lawn needs hibernation, like a bear in a den. Better not to bother the grass. The roots should rest without load. The snow layer does not count. But after filling the rink or walking with sculpting snow women, the lawn will definitely not stand it. In spring, grass will come out in shreds, bald spots will quickly turn yellow. Alas, only digging is able to help such a lawn. The grass will have to be re-planted.
Fragmented freezing or lawn mowing in winter is also not uncommon. During prolonged thaws, a dense crust forms on the snow.
The more irregularities on the green carpet (it is unrealistic to level the soil without special equipment), the more spots there will be in spring.
Wrong watering
I specifically focus on the word "wrong." Excess water is just as dangerous for some types of herbs as the lack. In rainy years drought-resistant crops suffer. In areas where they grow, it is urgent to do additional drainage - dig narrow grooves around the perimeter to drain water. 
Source: www.autopoliv-gazon.ru
Inadequate watering is dangerous for bluegrass herbs.
On hot days, when the sun is at its zenith, it is advisable not to include autowatering. Drops work like lenses, grass is burned this time. The lawn is not ready for tanning and water procedures at the same time - these are two.
In warm regions, where everything planted, no matter what, this problem is not so obvious. In the middle lane, in the Urals, in Siberia, and other regions with unstable weather, plants are not used to heat, it is stress for them.
The contrast of cold water pumped from the well and hot air is disastrous.
Oh these animals
When yellow spots began to appear on the green carpet in the fall, my husband and I could not establish the cause of the defeat for a long time. Everything became clear when they saw the canine "trophies". 
Source: wagwalking.com
It turned out that the neighbor's dog got into the habit of running on our lawn. When there was little excrement, the lawn digested them. But when there were too many "fertilizers", the grass began to grow poorly.
Bad haircut
Blades of grass also suffer from the wrong cut. When the herbage is too tall, more than 8 cm, the grass dries, interferes with the roots. They lack light, oxygen. When too many are cut, there are fewer than 5 cm, the lawn dries quickly. With a dense landing, this is especially noticeable. The roots begin to bare. Blades of grass dry quickly.
Solving yellowing problems
What to do depends on the causes of impaired grass growth. If you regularly feed the lawn, add nitrogen in spring and summer, and in the fall phosphorus, potassium and calcium in a ratio of 2: 1: 1, everything will be in order. Some forget about aeration - they use a pitchfork or special equipment to pierce the sod to a depth of 30 cm.
Plant felt should be removed periodically; it accumulates after cutting. The procedure is called scarification. Personally, I comb the lawn with a fan rake so as not to tear out pieces of grass. I carry out the procedure in a year, this is enough. Before winter, it is useful to mulch the lawn with humus. It creates a loose layer, the roots breathe. If you take good care of the lawn, it will not turn yellow, and a slight "malaise" is quickly treated.
