Yield and economic benefits of late planted short-season cotton versus full-season cotton relayed with garlic

• The optimum plant density was 3 plants m−2 for full-season cotton and 9 plants m−2 for short-season cotton in the garlic-cotton cropping system.
• Cotton productivity is dependent on soil fertility for full-season cotton but not for short-season cotton.
• Short-season cotton consumed less labor and material input and provided significantly more net revenue than full-season cotton.

Relay intercropping of garlic with full-season cotton is currently one of the dominant cropping systems in China, but the net benefit is decreasing because the system is labor-intensive. Direct planting of short-season cotton after garlic harvest may increase net revenue through reducing labor and material input. Three field experiments were consecutively conducted in Jinxiang County of China, to determine the effects of plant density and soil fertility on yield, yield components, boll load and leaf senescence in the 1st and 2nd experiments. In the third experiment, we compared the economic benefits of the two cropping systems. Data from the 1st experiment showed that plant density affected yield and yield components, with the optimum plant density being 3.0 plants m−2 for full-season cotton and 9.0 plants m−2 for short-season cotton. In the 2nd experiment, the seedcotton yield of full-season cotton was 9.1% higher under high than medium soil fertility, but there was no yield difference between the two soil fertility levels for short-season cotton. Full-season cotton exhibited larger boll load, earlier leaf senescence and lower boll weight under medium than high fertility. Results of the third experiment showed that seedcotton yield or output value of short-season cotton was 14.5% lower than that of full-season cotton, but the gross return for short-season cotton was 69.2% higher than that for full-season cotton because the short-season cotton required 27.3% less labor and material inputs. The overall results showed that late planted short-season cotton after garlic harvest can be a promising alternative for enhancing the benefits of garlic-cotton production in China.