Sugarcane Biochar as an Amendment for Greenhouse Growing Media for the Production of Cucurbit Seedlings

Abstract

Louisiana sugarcane farmers in 2016 harvested 11.7 million Mg millable sugarcane from 163,000 ha, producing 1.47 million Mg of raw sugar and an estimated 3.5 million Mg of bagasse. Even though Louisiana sugar mills use 80 to 90% of the bagasse for fuel production, another 350,000 to 700,000 Mg of bagasse accumulates each year. The conversion of the excess bagasse into biochar is an excellent option with numerous uses. Research was conducted to determine the impact of sugarcane biochar as an amendment to soilless planting media for the production of cucurbit seedlings. Two biochars were combined by volume with a commercial certified organic soilless growing media into 5 combinations (0%:100%, 25%:75%, 50%:50%, 75%:25%, and 100%:0%, biochars and growing media, respectively). Squash (Cucurbita pepo L.) var. 'Enterprise' and cantaloupe (Cucumis melo L.) var. 'Magnum .45' were planted in each of the 5 different planting mixtures. The higher heating value (HHV), lower heating value (LHV), and fixed carbon (FixC) were greater for the standard bagasse biochar (SBB), therefore, making it more valuable as a potential fuel source than the pneumatic bagasse biochar (PBB). All of the biochar mixture combinations compared favorably to the commercial media with low bulk densities (0.11 to 0.14 g cm -3 ) and high water holding capacities (80-87%). In respect to seedling production, the biochars (SBB and PBB) performed well, especially at the 25 and 50% levels for both plant species. The squash seedlings responded better at the 75% level than the cantaloupe seedlings, which reflect differences in nutrient requirements. The 100% biochar growing media are not recommended because both plant species often had a decrease in organic matter. These results indicate that the volume of a standard soilless greenhouse growing media can be successfully extended by adding 25 to 50% sugarcane biochar without a reduction in squash and cantaloupe seedling production. Future research should investigate the impact of additional plant species, as well as different biochar sources on seedling production.

Effects of Biochar on Container Substrate Properties and Growth of Plants—A Review

“…In addition to production conditions, biochars could be made from varying feedstocks, which would contribute to differences in physical and chemical properties ( Table 1). The feedstocks could be waste materials such as green waste [18], forest waste [46,47], wheat straw [5], sugarcane bagasse [48], rice hull [49], crab shell [50] and Eucalyptus saligna wood chips (byproduct of construction, fuel-wood and pulp wood) [51]. Biochars could also be made from non-waste materials such as holm oak [52], conifer wood [53], citrus wood [54] and pine wood [6,[55][56][57].…”

“…The biochars made from different feedstocks could have different physical and chemical properties, which should be taken into account when they are incorporated in containers. Sugarcane bagasse z 343 n n n 0.11 5.8 n n n n n n n n n n [48] Sugarcane bagasse z 343 n n n 0.11 6.1 n n n n n n n n n n [48] Switchgrass z 1000 n n n 0.10 10.8 3.5 n 1.3 79.0 1.20 6.60 n n n n [69] Wheat straw 600 n n n 0.31 10.0 1.0 n 1.0 79.3 n n n n n n [70] Wheat straw n n n n 0.24 9.5 2.5 n n n 0.003 0.10 0.002 0.004 0.0009 n [5] Note: Production temp: production temperature; CC: container capacity; AS: air space; TP: total porosity; BD: bulk density; EC: electrical conductivity; CEC: cation exchange capacity. Pyrolysis was the biochar production method, unless indicated otherwise.…”

Evaluation of Biochar and Compost Mixes as Substitutes to a Commercial Propagation Mix

“…'Enterprise') seedlings in mixes of 75% (by volume) standard bagasse BC with the rest being commercial growing mix were similar to the ones in the control while those of the cantaloupe (Cucumis melo var. 'Magnum 45') seedlings were lower than the ones in the control [44]. Similarly, the FWs and DWs of green bean var.…”

Mixed Hardwood and Sugarcane Bagasse Biochar as Potting Mix Components for Container Tomato and Basil Seedling Production

“…Sugarcane bagasse biochar and pinewood biochar improved the growing mix properties for bean and cucurbit seedlings production [31]. The pruning residue biochar produced from pyrolysis at 500 • C can improve growing media properties for soilless vegetable production [13,39]. The biochar could also replace perlite and has a liming effect when incorporated into a soilless substrate [40,41].…”

“…Pyrolysis biochar is generated from biomass thermo-chemical decomposition in oxygen-depleted or oxygen-limited atmosphere [7][8][9]. Biochar has been considered as a sustainable material because it can be derived from various sources, such as pinewood [3,10,11], 2 of 14 green waste [12], wood, sugarcane bagasse [13], straw [14][15][16][17][18], bark [19], rice hull [20], and wheat straw [16,21]. For the same reason, biochar properties can vary widely [22].…”