Key Cultivation Techniques for Intercropping Cassia obtusifolia with Arisaema

The medicinal herb Cassia obtusifolia is the dried mature seed of Cassia obtusifolia or Cassia tora of the Fabaceae family. It has the effects of moistening the intestines and relieving constipation, lowering blood lipids and improving eyesight, and treating constipation, hyperlipidemia and hypertension. The demand for this medicinal herb is large and its price is relatively stable. Arisaema, also known as Arisaema heterophyllum, is a perennial herbaceous plant with a plant height of 30-45 cm, monoecious, and its tuberous corm is used as medicine. Cassia obtusifolia is an annual semi-shrubby herb. Arisaema generally grows in cool, moist forest environments and is not tolerant of strong light and high temperatures. Cassia obtusifolia can provide a relatively good shaded environment for the growth of Arisaema. At the same time, Arisaema likes water and fertilizer, and only with sufficient base fertilizer can it achieve high yield. Intercropping Cassia obtusifolia with Arisaema can increase the yield per unit area of land, improve the utilization rate of soil fertilizer, and increase income.

Cultivation techniques:

1. Site selection, land preparation and fertilization.

Cassia obtusifolia likes high temperatures and a humid climate. It is suitable for growing in sandy loam, humus soil or soil with medium fertility. Flat land or sunny sloping land with good drainage and irrigation conditions should be selected. Arisaema is a short-stemmed, shallow-rooted plant that likes water and fertilizer, and is suitable for planting in fertile sandy loam. It is afraid of drought and also afraid of long-term waterlogging. It is cold-resistant, and seedlings can overwinter in the field, but plants in their second year of growth cannot overwinter in the field. Before planting, select the plot according to growth habits, and in combination with land preparation apply 3000-4000 kg of barnyard manure or compost per mu, 40 kg of diammonium phosphate (or 130 kg of superphosphate), and 15 kg of potassium sulfate per mu. Spread the fertilizer evenly, then plow and prepare the land to make beds. Generally, flat beds of alternating sizes with widths of 1.2 m and 0.3 m are made. The length of the beds depends on the plot, and it is best to make them convenient for drainage and irrigation. Plant Arisaema in the large beds and Cassia obtusifolia in the small beds.

2. Propagation methods. Arisaema is divided into two propagation methods: tuber propagation and seed propagation, and tuber propagation is mostly chosen.

Tuber propagation: Around the "Qingming" and "Guyu" solar terms, open furrows on the prepared bed surface with a furrow depth of 5-7 cm, and plant at a plant spacing of 12-15 cm with the buds of the tubers facing upward. After planting, cover with mixed fertilizer and fine soil 3-4 cm thick. Small tubers should be covered with shallow soil, while large tubers should be covered deeper. Each mu requires 40-60 kg of large tubers or 25-35 kg of small tubers for planting.

Cassia obtusifolia is propagated by seed. In mid-to-late April, select plump seeds free from insect damage, soak them for 24 hours in 50°C warm water with added Xin Gao Zhi Mo, remove them and dry them slightly, then sow in furrows at a row spacing of 60 cm, with a furrow depth of 5-7 cm. After sowing, cover with 3 cm of soil, press lightly, and water. Seedlings can emerge in 10-15 days. Begin thinning when the seedlings are about 5 cm tall. When the seedlings are 15 cm tall, in combination with cultivating and weeding, thin to a plant spacing of 30-40 cm.

3. Field management. Because Arisaema has shallow roots, cultivation should be shallow rather than deep. Loosen the soil frequently to keep the land loose, and remove weeds in the field in a timely manner. Before Cassia obtusifolia closes its rows, in combination with cultivation, apply 1000-1500 kg of dilute human and animal manure plus 15 kg of urea per mu as a topdressing. Apply another topdressing in mid-June (the same method as the previous application). Late July is exactly the vigorous growth period of Arisaema; apply 1500-2000 kg of decomposed manure per mu as a topdressing. In late August, apply 10 kg of urea and 15 kg of superphosphate per mu as a topdressing. During the growth period, pay attention to watering, and watering should be done in small amounts and multiple times. During the rainy season, pay attention to drainage to prevent waterlogging. After Arisaema blooms, except for plants retained for seed, the inflorescences of the remaining plants should be cut off in a timely manner to help increase yield.

4. Harvesting and processing.

Cassia obtusifolia gradually matures around the Autumn Equinox (late September). When the pods turn yellow-brown, begin harvesting. Cut down the whole plant and dry it in the sun, thresh out the seeds, and remove all impurities to obtain the medicinal herb.

For Arisaema propagated by corms, harvest by digging when the leaves turn yellow and withered from the Autumn Equinox to the Cold Dew solar term of the same year; for those raised from seeds, harvest after two years. Dig out the corms, remove the stems and leaves, shake off the soil, put them into gunny bags (filling 1/3 of the bag is sufficient), place them on a wooden board and rub off the outer skin, pour them out and rinse with water, scrape the skin clean from the sunken areas with a bamboo knife, and then dry them in the sun.