Harvest index and residue factor of non-cereal crops in China

Harvest index(HI) and residue factor(RF) are of essentially significance for crop production research and crop residue quantity assessment.HI and RF of non-cereal crops in their main production provinces of China are reviewed according to field data collected from original papers published mainly during 2006-2010.HI of soybean varied between 0.35 and 0.47 whereas RF between 1.13 and1.86 across six provinces,and the average was 0.42 and 1.50,respectively.Tubers including potato,sweet potato,and cassava had HI between 0.55 and 0.77 whereas their between 0.30 and 1.17 across eleven provinces.The average HI and RF was 0.59 and 0.71 for potato,0.69 and 0.45 for sweet potato,and 0.64 and 0.50 for cassava,respectively.The average HI and RF for cotton were 0.15 and 2.91,with a range of 0.12-0.18 and 2.41-4.09 respectively.Peanut had HI between 0.41-0.54 and RF between 0.85-1.43 across six provinces,and the average was 0.50 and 1.14,respectively.Canola had HI 0.24-0.28 and RF 2.57-3.17 across six provinces,and the average HI and RF were and 2.87,respectively.Sunflower had HI between 0.21 and 0.40 whereas RF between 1.50 and 3.76 across four provinces in Northwest and North China,and their average HI and RF were 0.32 and 2.63 respectively.In Henan and Hubei provinces,the average HI and RF were 0.34 and 2.01 for sesame.Sugarbeet had a higher average HI 0.71 with a range of 0.60-0.85,its RF varied between 0.18-0.67,with an average of 0.43.HI and RF of sugarcane was 0.70 and 0.43 for Fujian province only.Tobacco had HI between 0.52-0.67 and RF between 0.49-0.92 across seven provinces,the average HI and RF was 0.61 and 0.71,respectively.In near future,there will be a potential trend to decrease the HI to approach higher crop residue yields,along with substantial improvement of the economic product yield due to increase in biomass yield.