Summer Solstice Farming

Around the Summer Solstice, maize and soybeans across Northeast China enter vigorous growth, full-scale field management unfolds, and crops enter a period of rapid development.
Maize management during jointing. Spring maize in Northeast China enters jointing around the Summer Solstice, with stem internodes beginning to elongate rapidly and young ears differentiating and developing inside the stalk. Jointing is a key stage for determining both ear number and kernels per ear. Management centers on applying 拔节肥 at 8–10 kilograms of urea per *mu* to promote stem elongation and young-ear development; intertilling and earthing up in combination with fertilization to encourage root growth and lodging resistance; and controlling pests and diseases, with corn borer entering a key treatment window and treated with phoxim or Bt preparations, while aphids, leaf spot, and other problems require simultaneous monitoring. Management during jointing directly affects ear number and final yield.
Soybean management during flowering. Soybeans in Northeast China enter flowering around the Summer Solstice, with blossoms opening and pod formation beginning. Flowering is a crucial stage for determining pod number and seed number. Management centers on applying 花荚肥 (*flower-and-pod fertilizer*) at 5–8 kilograms of compound fertilizer per *mu* to promote flowering and pod setting; intertilling and soil loosening in combination with fertilization; and controlling pests and diseases such as soybean pod borer, aphids, and leaf spot as they enter treatment windows. Management during flowering directly affects pod number and final yield.
Rice management from peak tillering to early jointing. Rice in Northeast China moves from peak tillering into early jointing around the Summer Solstice, with effective tillers largely established and plants beginning to transition into elongation growth. Management includes 晒田控苗 once the target tiller number has been reached, draining and drying fields for 7–10 days to suppress unproductive tillers and encourage deeper rooting; applying 拔节肥 after re-flooding, mainly potash, at 5–8 kilograms of potassium chloride per *mu*; and controlling rice blast, sheath blight, and other pests and diseases as they enter treatment windows.
Pasture management. Pastures in eastern Inner Mongolia remain in vigorous growth and livestock grazing continues. Herders implement rotational grazing systems to make rational use of grassland resources.

Around the Summer Solstice, Northwest China enters a crucial stage of summer management: spring wheat moves into heading and flowering, cotton enters budding, and the winter-wheat harvest in southern Xinjiang expands fully.
Spring-wheat management during heading and flowering. In the Hexi Corridor of Gansu and the Yellow River irrigation districts of Ningxia, spring wheat enters heading and flowering around the Summer Solstice, with young ears emerging and flowering and pollination beginning. This is a crucial stage for determining kernel number per ear. Management centers on securing water supply because demand is high during heading and flowering, with timely irrigation where soil moisture is insufficient, generally 40–50 cubic meters per *mu*; controlling wheat rust, aphids, wheat midges, and other pests and diseases as they enter critical treatment periods, particularly wheat midge adults laying eggs on the ears and larvae feeding on the juice of developing kernels, which requires spraying at heading; and guarding against 干热风 through foliar fertilizer applications that improve stress resistance. Management during heading and flowering directly affects kernel number and final yield.
Cotton management during budding. Cotton across Xinjiang enters budding around the Summer Solstice as flower buds begin to form and develop, making this a key stage in determining boll number and yield. Management centers on applying 蕾肥 (*bud fertilizer*) at 10–15 kilograms of compound fertilizer per *mu* to promote bud development and plant growth; timely pruning and topping, including removal of side growing points, to control vegetative growth and promote reproductive growth; and controlling cotton bollworm, aphids, cotton spider mites, and other pests as they enter key treatment windows. Management during budding directly affects boll number and final yield.
Large-scale winter-wheat harvest in southern Xinjiang. Winter wheat in the Tarim Basin enters large-scale harvest around the Summer Solstice, with ears turning fully yellow, kernels becoming plump and hard, and the crop reaching physiological maturity. Farmers seize clear weather for harvesting, with combines operating day and night and completing harvesting, threshing, and cleaning in a single operation. Grain is promptly dried and stored after harvest, and fields are immediately plowed.
Orchard management. Apples, fragrant pears, grapes, and other fruit crops in southern Xinjiang enter fruit enlargement. Growers strengthen water and nutrient management through 膨果肥, mainly potash, and control pear psylla, aphids, spider mites, codling moth, and other pests. Grapes enter the young-fruit stage and require fruit thinning and summer pruning.
Specialty crops. Potatoes around Dingxi, Gansu, move from flowering into tuber formation and require stronger water and nutrient management through 结薯肥, mainly potash, together with late-blight control. Goji in Ningxia moves from fruit development into maturity and harvest, with farmers seizing clear weather to pick and dry the crop. Processing tomatoes in Xinjiang move from flowering into fruit set and require stronger water and nutrient management.

Around the Summer Solstice, the winter-wheat harvest across North China is largely complete, summer maize and summer soybean sowing is fully finished, and farmland shifts into summer management as the agricultural rhythm moves from “harvesting and sowing together” toward “field management.”
Winter-wheat harvest largely complete. By the Summer Solstice, the winter-wheat harvest across the North China Plain is largely finished and grain has been brought safely into storage, while wheat-straw handling is completed at the same time through straw incorporation or baling and removal from fields. After wheat harvest, land is immediately plowed or directly seeded without tillage in preparation for summer crops. Wheat harvesting is generally completed between Grain in Ear and the Summer Solstice, and its conclusion marks the end of the first stage of the “三夏” rush.
Summer-maize seedling management. Summer maize enters a critical seedling-management stage around the Summer Solstice as plants move into rapid growth after emergence. Management includes inspecting stands and filling gaps by transplanting where plants are missing; thinning and final stand establishment at the 3–4 leaf stage, leaving 1–2 strong plants per hill and removing weak or diseased seedlings; applying 苗肥 at 5–8 kilograms of urea per *mu*; intertilling and weed control at a depth of 5–8 centimeters in combination with fertilization; and controlling seedling-stage pests such as cutworms, mole crickets, aphids, and corn borer. Growth during the seedling stage directly affects ear number and final yield.
Summer-soybean seedling management. Summer soybeans enter a crucial seedling-management stage around the Summer Solstice, including stand inspection and gap filling, thinning and final stand establishment with 2–3 strong plants per hill, intertillage and weed control, application of 苗肥 at 3–5 kilograms of urea per *mu*, and control of seedling-stage pests and diseases such as aphids and cutworms.
Orchard management during peak fruit enlargement. Apple-, pear-, and peach-growing areas across North China enter peak fruit enlargement, with young fruit developing rapidly in a crucial stage of quality formation. Growers apply 膨果肥, mainly potash, at 10–15 kilograms of potassium sulfate per *mu* to promote fruit development and quality; carry out summer pruning by removing vigorous upright shoots and overly dense branches to improve ventilation and light penetration and promote flower-bud differentiation; and strengthen control of apple ring rot, pear scab, peach aphids, oriental fruit moth, spider mites, and other pests and diseases as they enter key treatment windows.
Vegetable management. Open-field vegetables across North China enter rapid growth and peak harvest, with cucumbers, beans, eggplants, peppers, tomatoes, and other summer vegetables reaching the market in large quantities. Water and nutrient management and pest and disease control need to be strengthened, while after the Summer Solstice, rising temperatures make protection against heat and drought increasingly important.

Around the Summer Solstice, the plum-rain season reaches its peak across the middle and lower Yangtze, bringing prolonged rain, high humidity, and limited sunshine. Early rice moves from heading and flowering into grain filling, making flood control and rice management equally important.
Flood control during the peak plum-rain period. Around the Summer Solstice, the plum-rain season reaches its peak across the middle and lower Yangtze, with large rainfall totals and long-lasting precipitation making this the most concentrated period of annual rainfall. Farmers need to inspect drainage systems continuously and ensure that the “三沟” remain unobstructed to prevent standing water and waterlogging. Low-lying fields are particularly vulnerable and require drainage plans in advance. This is also a critical flood-control period for reservoirs and embankments, and water-level changes need to be monitored closely.
Early-rice management from heading and flowering into grain filling. Early rice across the Yangtze River basin moves from heading and flowering into grain filling around the Summer Solstice, with young panicles emerging, flowering and pollinating before the crop enters grain filling. Management centers on maintaining a shallow water layer of 3–5 centimeters without allowing fields to dry, applying 穗肥, primarily potash, at 3–5 kilograms of potassium chloride per *mu*, and monitoring weather closely. Persistent cloudy and rainy conditions during the plum rains can impair pollination and seed set, increasing the number of unfilled grains, while temperatures of 35°C or above can render pollen inactive. Pest and disease management must also be strengthened because rice blast, sheath blight, planthoppers, and other problems enter a high-incidence period under the hot and humid conditions of the plum rains. Management during grain filling directly affects seed-setting rate and thousand-kernel weight.
Pest and disease control. High temperatures and humidity during the plum rains bring rice pests and diseases into a high-incidence period. Key targets include rice blast—leaf blast and panicle-neck blast—treated with tricyclazole or isoprothiolane; sheath blight, treated with validamycin or difenoconazole + propiconazole; rice planthoppers, treated with imidacloprid or buprofezin; and stem borers, treated with dimehypo or Bt preparations. Farmers need to strengthen field inspections and intervene promptly when pests or diseases are detected.
Vegetables and aquaculture. During the plum-rain season, open-field vegetables across the Yangtze basin grow more slowly and pests and diseases occur readily, making drainage and disease control especially important. Greenhouse vegetables require stronger ventilation and humidity reduction. In aquaculture, low atmospheric pressure and high humidity during the plum rains increase the risk of oxygen depletion and pond overturning, so farmers need to strengthen aeration and water-quality management.

Around the Summer Solstice, agricultural activity across Southwest China enters summer management: the winter-wheat harvest is largely complete, potatoes remain in tuber enlargement, and spring-tea picking is fully finished.
Winter-wheat harvest largely complete. By the Summer Solstice, winter-wheat harvesting in the Sichuan Basin is largely finished, with grain safely stored and fields plowed in preparation for middle-season rice or other summer crops.
Potato management during peak tuber enlargement. Spring potatoes in the main producing areas of Yunnan, Guizhou, and Sichuan enter peak tuber enlargement around the Summer Solstice, with underground tubers expanding rapidly in a crucial stage for both yield and marketable quality. Management centers on applying 结薯肥, primarily potash, at 8–10 kilograms of potassium sulfate per *mu*; controlling late blight, the crop’s most important disease, using mancozeb or metalaxyl every 7–10 days for 2–3 consecutive applications; irrigating at the proper time to secure adequate moisture without allowing waterlogging; and intertilling and earthing up to prevent tubers from being exposed to light and turning green.
Spring-tea picking fully complete; summer garden management advances comprehensively. Spring-tea harvesting is completely finished across Sichuan, Guizhou, and Yunnan, and growers move fully into summer garden management through immediate pruning after spring harvest to encourage summer and autumn shoots, application of summer fertilizer mainly based on nitrogen, and control of tea green leafhoppers, tea geometrid moths, tea blister blight, and other pests and diseases as they enter critical treatment windows.
Orchard management. Citrus-growing areas across Southwest China enter fruit enlargement and require stronger water and nutrient management through 膨果肥, mainly potash, together with control of citrus red mites, leaf miners, citrus canker, anthracnose, and other problems. Loquat harvesting is largely complete and orchards move into postharvest management through pruning and fertilization.

#### (1) Mainland South China
Early-rice grain filling and flood control during “龙舟水.” Early rice in South China enters grain filling around the Summer Solstice, with kernels becoming increasingly full in a crucial stage for determining thousand-kernel weight. Management centers on keeping fields moist through shallow-water or moist irrigation without allowing them to dry; applying 粒肥 (*grain-filling fertilizer*), mainly potash, at 3–5 kilograms of potassium chloride per *mu* to promote full kernels; preventing heat-forced maturity by applying deeper water when temperatures reach 35°C or above, generally 5–10 centimeters, to lower field temperature; and guarding against “龙舟水”, which continues around the Summer Solstice with frequent heavy rainfall, requiring farmers to keep drainage systems unobstructed and prevent flooding.
Spring-peanut and spring-maize management. Spring peanuts move from peak pod setting into early maturity, with pods enlarging rapidly and some early cultivars beginning to ripen. Management focuses on controlling peanut leaf spot, aphids, cotton bollworm, and other pests and diseases and harvesting early cultivars at the proper time. Spring maize moves from grain filling into maturity, with kernels becoming full; water supply must be secured because drought can reduce thousand-kernel weight, while corn borer, aphids, leaf spot, and other pests and diseases require control.
Tropical-fruit management. Early lychee cultivars such as “三月红” and “白糖罂” enter peak maturity and harvest, while middle- and late-season cultivars including “妃子笑”, “桂味”, and “糯米糍” move from fruit enlargement toward early maturity and require stronger water and nutrient management. Mangoes enter maturity and harvest, with farmers seizing clear weather to pick, grade, pack, and market the fruit. Citrus enters fruit enlargement and requires control of excessive summer-shoot growth together with citrus red mites, leaf miners, canker, and other problems.
Vegetables and aquaculture. Open-field vegetables across South China enter rapid growth and peak harvest. Rising temperatures bring pests and diseases into a high-incidence period and require stronger prevention and control. In aquaculture, “龙舟水” brings continuing flood risk, requiring more frequent pond inspections, stronger water-quality management, and prevention of oxygen depletion and pond overturning.
#### (2) Taiwan
Rice: The first rice crop in central Taiwan—including Changhua, Yunlin, and the Chianan Plain—enters peak harvest around the Summer Solstice, with panicles fully yellow and kernels plump as farmers seize clear weather for cutting. In southern Taiwan, particularly the Kaohsiung–Pingtung region, the rice harvest enters its final stage. In northern Taiwan, including Taoyuan and Hsinchu, rice moves from heading into grain filling.
Vegetables: Around the Summer Solstice, summer vegetables across Taiwan enter peak harvest, with cucurbits such as watermelon, cucumber, and muskmelon, along with beans and fruiting vegetables, reaching the market in large quantities.
Fruit trees: Mangoes in southern Taiwan enter peak maturity and harvest, with cultivars such as Irwin and Jinhuang harvested intensively. Lychees likewise enter peak maturity and harvest, including concentrated harvesting of cultivars such as Yu Her Pau. Citrus enters fruit enlargement.
Tea: Summer management advances fully across tea gardens in central and southern areas such as Nantou and Chiayi, including pruning, fertilization, and pest and disease control. Tea gardens in northern districts such as Wenshan and Sanxia likewise enter full summer management.
Fisheries: Catches in waters around Taiwan continue to increase during the Summer Solstice. Coastal fishing vessels go to sea frequently and catch quality remains good.
Farmer’s proverbs and folk customs: Taiwanese folk tradition preserves the saying “夏至，風颱（台风）就欲到”—after the Summer Solstice, typhoon season is about to arrive, and coastal areas need to prepare accordingly. Another saying, “夏至吃荔枝，冬至吃汤圆”, links lychees with the Summer Solstice and tangyuan with the Winter Solstice, reflecting the seasonal food culture associated with the solar terms.