Lychee (or litchi) fruit trees are native to southern China and have been cultivated there on small plots for some 2000 years. Guangdong has the highest production of lychees in China today. Even though the fruit is highly prized, major lychee plantation expansion by corporations did not begin until about 1990. Now, some individual plantations cover as much as several hundred hectares (ha). The area of lychee plantations in Guangdong alone in 1980 was only about 2000 ha but by 2000 the planted area had expanded to some 300,000 ha (1).
During the 1990s, I traveled to many parts of Guangdong where I saw extensive land preparation for new lychee orchards as well as some already in production (Figure 1). These were the boom years for new lychee orchards. The following is a brief summary of what I saw and what I was told by agricultural experts and government officials regarding lychees.
Figure 1: Lychee plantings along Xinfengliang Reservoir, Guangdong (Photo by W. Parham, 1998).
Certain rules and regulations were developed by agricultural experts regarding construction of new orchards. For instance, farmers were instructed to avoid hillsides with slopes of 25 degrees or greater because of an increased chance of soil erosion. Soil erosion had been a serious problem on much of Guangdong’s countryside in earlier years. Yet, the restriction for not planting lychee orchards on such steep slopes was ignored by many planters (Figure 2).
Figure 2: Lychee (Litchi chinensis) orchards near Maoming, Guangdong planted on erosion-prone land having slopes of 25 degrees or greater. Longan (Dimocarpus longan), a fruit tree related to the Lychee, is mostly planted on the lower slopes. Soil erosion is evident on these steep slopes (Photo by W. Parham, 1999).
Preexisting hilltop tree cover was intended to be preserved for use as a “conservation forest.” Researchers found that fruit tree growth was improved where conservation forests were left in place as well as soil erosion from running water being reduced. In some cases farmers planted drought tolerant pine, olive, chestnut, or eucalyptus trees on hill tops as conservation forests. Nevertheless, many farmers extended their plantations to the hill tops at the expense of the conservation forests. Their hope was to increase fruit production for their personal income. By doing so, many trees of the conservation forest were cut leaving only a scattered few behind and the conservation benefits were lost or reduced (Figure 3).
Figure 3: Terraces near Heyuan, Guangdong awaiting lychee plantings. Conservation forest here is almost nonexistent, and terrace erosion is underway (Photo by W. Parham, 1998).
Lychee and longan trees generally were planted 3.5 to 5.0 m (~11 x 15 ft.) apart. In some cases the soil beneath the trees was left bare, and in other cases the soil had a grass cover, sometime tall grasses. A university agriculturalist told me that workers who pick the fruit do not like to stand in long grass because they were afraid of being bitten by poisonous snakes, a real concern.
In the Gaozhou area, where lychee production is large and where there is at least 75 percent slope land, fertilizer consisted of chicken manure and “city waste.” City waste was used mostly because of it’s low cost; large piles of it dotted the orchards.
City waste consisted mostly of a mixture of organic matter, coal ash, plastic, glass, and metal, certainly a low quality fertilizer. Two to four kilograms (~5 to 10 pounds) of city waste was placed in the hole dug for each new tree, the tree inserted, and the hole covered with soil. Many farmers kept the soil surface clear of vegetation beneath the fruit trees to avoid competition for nutrients and water needed by the trees. Because many orchards were situated on hillsides, water erosion easily removed the soil around the fruit trees and uncovered the city waste. Some of the waste was carried down slope by running water and then scattered further across the land by the wind (Figure 4).
Figure 4: City waste used as fertilizer in a lychee plantation. The waste material are exposed by water erosion and scattered by wind; near Gaozhou, Guangdong (Photo by W. Parham, 1999).
In some cases, the city waste in fact was medical/hospital waste. Nevertheless, the farmers still used this waste for fertilizer (Figure 5). Obviously, handling medical/hospital wastes could be hazardous to orchard workers. The scatter of wastes furthered the potential for the spread of serious health problems. The degraded hill-slope soils needed fertilizer to support fruit tree growth but instead the “low-cost” medical-waste fertilizer threatened to produce health problems in lychee orchards.
Figure 5: Exposed medical/hospital waste used as lychee tree-fertilizer; near Gaozhou, 1999. Arrows point to medical waste (Photo by W. Parham, 1999).
I first saw medical/hospital waste being used as fertilizer in Gaozhou lychee orchards in 1999 (Figure 5). I pointed this out to a group of agriculture experts and government officials while we visited one orchard and was told by a senior government official that “This was just an isolated case and not to worry.” Later that day a few miles away I spotted medical waste being used in a state-run lychee orchard. I restated my concerns and was told this time by a government official that the use of medical waste as fertilizer would be stopped. Four years later, I revisited this orchard along with agricultural experts and government officials and was asked to see if I could find any medical waste. I said that I trusted that it was no longer being used. Later however, one of their assistants took me aside to tell me that even though medical waste was no longer being used at this site that such waste was still being used in most other areas nearby.
The observations and discussions above took place some 15 to 25 years ago so I realize that much has changed, perhaps for the better. A cursory look at Google Earth images of the Gaozhou/Maoming area showed extensive orchards but little evidence of associated erosion. In 2005, Beijing installed China’s first medical-waste incinerator as an opening to its countrywide plan.
W. Parham, Nov., 2017
Reference cited:
- Xuming Huang, FAO, 6. Lychee production in China, http://www.fao.org/docrep/005/ac684e/ac684e07.htm
South China Degraded Land Issues 