Photo: susanne aigner
Lentils in nutrition: legumes prove to be important sources of protein for humans and animals
Increasingly, native hulled crops are being grown – as a substitute to controversial imported soybeans. Legumes are a valuable food not only for livestock, but also for humans.
According to the fao (food and agriculture organization of the united nations), three quarters of all cultivated plant varieties have disappeared since 1900, in germany, for example, lentils, spelt and einkorn. Instead of many regional varieties, there are only a few genetically uniform and high-yielding cultivars. Worldwide, only about 30 plant species meet almost all the calorie needs of the world’s population, more than half of them with wheat, rice and corn.
But the more uniform the genetics, the higher the incidence of disease. Also, because they reduce pest infestation, our ancestors farmed with wide, multi-sectional crop rotations. In addition, a wide genetic diversity keeps fungal and viral diseases at bay and ensures healthy, abundant harvests. Today, new varieties that can cope with increasingly long drought periods and thrive in salty soil are also needed.
These challenges in arable farming can be overcome – among other things with traditional crops: hulse crops contain high amounts of vegetable protein, minerals and fiber, vitamin b, potassium, magnesium, phosphorus and iron. They are inexpensive, filling and, with their high nutrient and low energy density, ideal for vegetarians and vegans.
They help lower cholesterol, prevent constipation and stimulate intestinal activity. Because the carbohydrates are absorbed slowly into the bloodstream, these low-fat crops can also be eaten by diabetics. To draw attention to their importance in human nutrition, the fao declared 2016 the international year of the lentil fruit.
Lentils thrive in dry soil
As one of the oldest crops, lentils were first cultivated more than 8.They have been cultivated in the mediterranean and in the orient for thousands of years. 100 years ago, they were still a dominant feature of the cultivated landscape in germany: from the harz mountains to the middle reaches of the elbe river, there were other varieties adapted to the respective conditions. Together with cereals, they were cultivated on poor soils.
But since 1960, lentils have disappeared from the fields: the labor input was too high, the yields too uncertain. For industrial agriculture, their cultivation was no longer profitable. Lentils are produced cheaper abroad: rough growing areas can be found in canada, agypt, india, pakistan and turkey, but also in the u.S., australia and chile, as well as in france and spain.
They grow under dry conditions on calcareous, stony, alkaline to slightly acidic soil. In very dry growing areas, the plants ripen early. All seeds that have formed by then are harvested. On the other hand, lentils are also susceptible to attack and – especially during heavy rainfall – are not very stable, which is why they are often grown with so-called support crops: barley, oats, spelt but also with peas and field beans. In this way, they not only ripen more evenly, but also grow higher than in pure culture.
For about 20 years, scientists at the university of gottingen have been investigating different varieties and generations of lentils in the field. Research focuses on the ability to adapt to extreme weather conditions such as drought and heavy rainfall. In addition to the conservation of old varieties in gene banks, explains bernd horneburg of the genetic resources and organic plant breeding group, lentil varieties have been preserved primarily through cultivation in nurseries and on farms.
Eating lentils instead of meat
They have long been part of traditional swabian cuisine. In the 1950s, cultivation of the schwabische-alb lentils was discontinued. But for about 30 years, organic farmer woldemar mammel from lauterach has been trying to revive the cultivation of this old crop.
His commitment found enthusiastic imitators in the region: 75 farmers of the oko-producers’ association now cultivate "alb-leisa" alongside traditional crops such as buckwheat and gold-of-pleasure, various lentil varieties on a total of 280 hectares.
The varieties differ in coarseness and color. The earthy-tasting lentils, which are used in soups and stews, spreads, casseroles and fried dishes, are very popular. The black beluga or puy lentils, which retain their shape when cooked and are used in salads, are considered a delicacy. Red and yellow lentils are the preferred cooking ingredients in indian cuisine. Smaller varieties such as mountain or puy lentils taste particularly good when germinated.
Field beans with tuberous bacteria. Photo: susanne aigner
In terms of nutrition, lentils can even replace the equivalent amount of meat. Served with cereals, milk or eggs, a lentil dish covers the need for essential amino acids. The flat, round seeds contain up to 24 percent protein – although the protein content can be more than 30 percent depending on the variety.
In addition, they contain almost 60 percent carbohydrates and 11 percent fiber, with only 1.4 percent fat. They are also rich in iron, zinc, potassium, magnesium, phosphorus and contain vitamins a, b1 and b2. Lentils are indigestible when raw.
Food for insects in the field
Hulse crops are able to bind nitrogen from the air and fix it in the soil with the help of their nodule bacteria – between 35 and 115 kg per hectare, depending on the soil type. Ideally, the following crop is also supplied with nitrogen. This may eliminate the need to apply artificial nitrogen fertilizer to the following crop, whose nutrient supply is also increased by residual plant residues.
Perennial legumes improve the carbon balance in the soil. Their contribution to climate protection should not be underestimated. According to a practical handbook of the federal agency for nature conservation on the cultivation of legumes, they not only visually enrich the landscape, but are also food for insects and habitat for wildlife and soil breeders.
Because of all these useful properties, hulse crops are now used not only in organic farming. Overall, cultivation in germany actually doubled in 2015 compared with the previous year.
For the purpose of self-sufficiency, hulse fruits can also be grown relatively easily in the garden. Both bush and pole beans thrive best on sunny and wind-protected sites on light and humus-rich soil. The first beans can be harvested after only six weeks.
Broad beans – also known as sow beans, horse beans and broad beans – are particularly undemanding, versatile and not very sensitive to frost. Formerly more common in home gardens, they are now cultivated primarily as field fodder.
Peas are also easy to grow. They can be harvested for several weeks and can be used in a variety of ways. Interesting for the hobby gardener are the strong peas, peas and the tasty sugar snap peas, which are eaten together with the pods.