When planting seedlings of desert plants in the desert area under no irrigation condition, why the survival rate is so low and the growth is so poor? A recent research using desert plant Haloxylon ammodendron discovered that high desert surface temperature (≥50oC) is a major limiting factor under numerous desert habitats. It provides a novel idea for ecological control measures of desert. Professor MA Hao and his group from Nanjing Agricultural University and Xinjiang Agricultural University found this phenomenon and set out to tackle this problem. After several years of innovative research, they have developed a novel but simple and effective technique to deal this adverse factor. Their work, entitled "Non-watering and tube-protecting planting technique for Haloxylon ammodendron under desert and its extension", was published in SCIENCE CHINA Life Sciences（in Chinese）, 2014, Vol 42(3).
Desertification has been widely recognized to threaten the existence of human beings on the planet. Keeping desertification from expanding is an important aspect for the co-existence of human and the nature. Haloxylon ammodendron has been one of the preferred plants that are used for the ecological recovery and restoration of the deserts in northwest China, but its seedlings planted suffers a very low survival rate (≤10%) and grows poorly under non-watering condition in desert areas. The problem has become a pivotal limiting factor for the utilization of Haloxylon ammodendron in combating desertification.
The low survival rate and poor growth of the planted Haloxylon ammodendron seedlings is usually ascribed to desert drought. However, Professor MA Hao and his group found that under numerous desert habitats that are not lack of water in soil, the Haloxylon ammodendron seedlings planted under no irrigation condition also suffered very low survival rate and poor growth. They discovered through further investigation and simulation experiment that it is the high desert surface layer (0~2 cm) temperature (≥50oC) around the basal part of stem of Haloxylon ammodendron seedlings that causes the problem. But this adverse factor is often neglected during desert afforestation using Haloxylon ammodendron. Based on this discovery, they invented a non-watering and tube-protecting planting technique for Haloxylon ammodendron. The new technique uses tube to protect the seedling of Haloxylon ammodendron. The tube can effectively reduce the surface temperature of soil inside the tube in spring and summer, thus protecting Haloxylon ammodendron seedlings from suffering burns, and the damage of sandwich and small animal. The new technique need no watering during planting and can be used in either direct seeding or transplanting. Moreover, it can also be used in planting of other desert plants.
After several years' proof-test in many desert environments, this new planting technique has been found to be suitable for utilization in the desert habitats with higher ground water level or abundant wet sand layer and can effectively increase the survival rate (≥70%) and annual growth (>20%) of Haloxylon ammodendron seedlings. In last two years, the new technique has been extended approximate 1333.3 hm2 in the desert areas of Xinjiang, Gansu and Inner Mongolia of China.
This novel technique has been recognized by many experts and herdsmen as one of the effective measures to combating the desertification.
Source: Science China Press