Interplanting mountain rice in oil-tea camellia fields puts 80% of the empty space to use
Original title: Making use of 80% of the open space between trees -
Century-old mountain rice takes on a "new look"
Mountain rice is an ancient rice variety. Many landraces have no name and no known origin. Its yield is extremely low, but its drought tolerance is very strong. It grows tenaciously deep in barren mountain soil, and was only planted in small areas in isolated mountain villages. With socioeconomic development, mountain rice has mostly withdrawn from the agricultural stage and disappeared into the mountains and wilds.
In young stands of oil-tea camellia and Torreya grandis on the mountainside, mountain rice is interplanted, and every golden autumn brings a scene of abundant harvest. In recent years, in many places in Zhejiang, mountain rice, centuries old, has begun to shine again. Since ancient times, mountain rice has mostly been planted in the Yunnan-Guizhou-Sichuan region. How did it cross thousands of mountains and rivers to settle in Zhejiang? The one writing this "new look" is the mountain rice research team of the Zhejiang Academy of Forestry.
Traveling far to remote mountains in search of mountain rice
Oil-tea camellia and mountain rice "tied the knot", and this first innovation was born in Wuyi County, Jinhua City, Zhejiang Province. In fact, it was not accidental. Wuyi is one of Zhejiang's main oil-tea camellia production areas, with a total planting area of more than 70,000 mu. Although the prospects for planting oil-tea camellia are good, there is basically no output in the first 5 years. Even though the government provides certain subsidies, income still falls short of investment.
"If only we could interplant some crops, that would be great." During an academy-local connection event in 2010, Chen Shenan, owner of Zhejiang Bailinggu Technology Co., Ltd., asked Qian Hua, an expert at the provincial academy of forestry. Chen Shenan had more than 3,000 mu of young oil-tea camellia forest. Calculating the empty land area between the trees, it was as much as 80%, and he felt great pain over this.
This topic is highly relevant in practice. In recent years, oil-tea camellia has been vigorously promoted, and how to solve the problem of early-stage output and returns is a common worry for "people like Chen Shenan." If all the space were interplanted with short-season crops such as vegetables, how would the problems of pesticide pollution caused by pest control and weeding, and the short and concentrated sales period, be solved? If other dryland cash crops were planted, how could they tolerate the barren environment of newly opened mountain land? After thinking it over, Qian Hua thought of mountain rice.
Although mountain rice is not a new thing, it had long faded from the agricultural stage. Historically, in the Yunnan-Guizhou-Sichuan region, because there were many mountains and the natural environment was complex and diverse, mountain rice cultivation was very prevalent, and a large number of landraces were once preserved. However, with the rapid development of modern agriculture, most shifting-cultivation land has been returned to forest, and the area suitable for mountain rice cultivation has shrunk sharply. Even where it remains, it can only be found in remote mountain corners.
Mountain rice, tolerant of barren soil and drought, was exactly the best choice for interplanting! Soon afterward, Qian Hua led a team far to the Jino ethnic residential area in Xishuangbanna. According to records, this place was once the most important mountain rice production area in southern Yunnan. The road to finding seeds was extremely arduous. After repeated setbacks, everyone finally found mountain rice in a mountain forest on the China-Myanmar border. Within a few months, the group also went deep into mountainous areas in Guizhou, Sichuan, Fujian, as well as Jiangshan and Suichang in Zhejiang, and collected more than 20 mountain rice varieties in total.
After returning to Hangzhou, the research team conducted germination rate tests on mountain rice seeds. Upon measurement, they found that 15 varieties had a germination rate higher than 95%, which greatly encouraged everyone. At least the first step had been successfully taken.
Initial results after 5 years of selection and breeding
As soon as he heard about this, Chen Shenan also became quite interested in mountain rice and specifically set aside more than 10 mu of young oil-tea camellia forest for trial planting. There were 280 experimental plots in total, with the aim of obtaining important characteristic data for each variety through comparison, including the best sowing period, growth period, stability, adaptability, resistance, and yield, so as to work out a set of cultivation techniques and models suitable for forest-grain intercropping and mutual promotion.
"Unlike upland rice, mountain rice does not need a water layer throughout its life, and its drought tolerance, barren-soil tolerance, and stress resistance are all very outstanding." Qian Hua analyzed that the reasons mainly lie in the root system and leaves. "The root system of mountain rice is very developed, and its depth in the soil can reach 40 cm, allowing it to effectively absorb water. The cell sap concentration in its leaves is relatively high, giving it strong drought tolerance. Even if subjected to drought, it can quickly resume growth."
Trial planting found that growing mountain rice is very simple. During the growth process, fertilizer only needs to be applied 3 times to meet its nutrient requirements. For weeding, mulching film technology is used, with remarkable results and low cost. As for pest and disease control, because mountain rice has strong wild resistance, almost no pesticide spraying is needed throughout the process. What excited the researchers most was that in the first year of trial planting, the harvest was more than 300 jin per mu. The next year, Chen Shenan decided to expand the trial planting area to 500 mu.
After two years of comparative cultivation trials, the researchers preliminarily selected 5 mountain rice varieties, all very suitable for cultivation in the region. During this period, they also used modern molecular marker methods and sequencing technology to carry out marker identification of 20 mountain rice varieties, as well as sequencing analysis of different agronomic traits, to develop marker genes related to drought-tolerance traits in mountain rice.
On the basis of earlier variety screening, regional cultivation trials were also conducted this year on 7 mountain rice varieties. Qian Hua told reporters that the team has so far collected 28 mountain rice seeds. After 5 years of trial planting, two varieties, "Bailinggu No. 18" and "Bailinggu No. 5", have been preliminarily selected as the main promoted varieties and are now entering the variety approval stage. Through yield measurement of Chen Shenan's more than 3,000 mu interplanting base, the average yield of "Bailinggu No. 5" reached 489.7 jin per mu, and the average yield of the other main promoted variety was also 362.2 jin per mu.
Three difficulties in promoting mountain rice
The several mountain rice varieties selected and bred can all be called leading stars. They experienced the continuous 48-day high-temperature drought in 2013 and the prolonged low-temperature and rainy conditions in 2014, and only stood out after layer upon layer of trials. Even many local old farmers praised it highly, saying that rice could actually be grown on mountain slopes. But Qian Hua knew clearly that if mountain rice was to be promoted on a large scale, there were still three "roadblocks" to overcome.
First, cultivation techniques need to be improved and standardized. At present, mountain rice cultivation is a new undertaking for improving land and increasing grain output, and many techniques still need to be promoted and explored. For example, due to reasons such as tight time and low temperatures, some newly planting farmers this year did not sow in time or apply enough base fertilizer, which affected seedling growth and later heading and grain filling to a certain extent. The quality of management conditions has a relatively large impact on mountain rice. In addition, there are issues such as the selection of organic fertilizer quality and protection against damage by birds and animals, and so on. Growing mountain rice may seem simple, but there are quite a few skills involved.
The most troublesome issue is labor input. It is estimated that from planting and management to harvesting, one mu of mountain rice requires at least 8 labor-days. Now workers are hard to hire, and wages are quoted very high. Although some growers have introduced small rotary tillers, hill-drop seeders, rice harvesters, and other equipment to achieve "machine substitution for labor," these machines face many difficulties in practical application. In particular, because many mountain plots were not properly prepared in the earlier stage and contain many stones, machines often run poorly.
The third is the issue of grain quality. Qian Hua said that in the past, mountain rice was planted mainly to solve the problem of food and clothing. Therefore, judging from the mountain rice varieties collected from various parts of the country, they are mainly indica and glutinous types. With the development of the market economy, mid- to high-end rice varieties have emerged one after another. In terms of taste, mountain rice is hard to give an advantage, and the pace of improving grain quality urgently needs to be accelerated.
At present, in order to solve the taste problem, the research team has, through repeated research and ratio adjustment, used a blended configuration method to launch a composite mountain rice with both good nutrition and good taste. Qian Hua also said that in subsequent mountain rice breeding, more attention will be paid to the grain quality issue to adapt to market needs and consumer tastes, so that mountain rice can truly reach ordinary people's dining tables.
Reporters learned that the planting area of mountain rice in Zhejiang has reached more than 8,000 mu. Compared with the province's 1.4 million mu of mountain oil-tea camellia and Torreya grandis seedling bases, the potential for interplanting space is enormous. At present, the research team is stepping up the cultivation and recognition of excellent mountain rice varieties. Targeting different needs, they will tackle both ordinary mountain rice with yield as the main focus and high-end mountain rice with quality as the main focus, implementing quality-oriented development of mountain rice.