Quality and Field Growth Characteristics of Hydroponically Grown Long‐Mat Seedlings

Abstract

Looming labor shortages and lower efficiency demand a shift from the cultivation of seedlings via the traditional nutritive soil method (CK) to hydroponically grown long‐mat seedlings (HLMS), a new method of raising rice (Oriza sativa L.) seedlings. This study was conducted to investigate the seedling quality and field growth characteristics of HLMS. We examined the effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield and benefit/cost ratio compared with those of CK (as a control). A widely grown conventional japonica rice cultivar (Wuyunjing24) and an indica hybrid rice cultivar (6Liangyou9368) were used as test material. The HLMS and CK showed no significant differences in weight/height ratio, seedling emergence rate, N content of leaves or antioxidant enzyme activities after transplantation; however, HLMS exhibited a more vigorous root system, a significantly decreased leaf area index and an extended transplantation period. The mechanical transplantation quality of HLMS was similar to that of CK but showed a significantly improved force of root entanglement. Compared with CK, the dry matter accumulation of HLMS differed quite low at the early field growth stage, whereas increased rapidly at the late growth stage. The yield and benefit/cost ratio of HLMS were equivalent or superior to those of CK. Briefly, the seedling quality of HLMS was better than that of the control, and its mechanical transplantation quality was comparable to that of the CK, enabling high‐yield and high‐efficiency rice production.Core Ideas Hydroponically grown long‐mat rice seedlings is a novel seedling cultivation method that reduces labor costs and improves efficiency. The force of root entanglement of hydroponically grown long‐mat rice seedlings was significantly improved. The yield and benefit/cost ratio of hydroponically grown long‐mat rice seedlings were equivalent or superior to those of the control.

Enhancing Grain Yield and Operational Feasibility by Transplanting Young Hydroponically Grown Long‐Mat Rice Seedlings

“…The nursery management of HLMS was conducted in accordance with a previous study (Li et al, 2016b). A digital Temperature‐Humidity Recorder (ZDR‐20h, Hangzhou, China) was used to record temperature and relative humidity in the nursery greenhouse were recorded.…”

“…Each treatment of HLMS involved four nursery trays (0.28 × 4.0 m) (Li et al, 2012b), and the CMSS treatment used 24 nursery trays (0.28 × 0.58 m). The management of CMSS and HLMS was performed according to the standards proposed by Li et al (2016b).…”

“…We have established a novel technology specifically adapted for China's rice production conditions. The results showed that the grain yield and economic benefit of HLMS were equivalent or superior to that of conventional mat seedlings raised in soil (CMSS) based on preliminary experiments (Li et al, 2016b; Lei et al, 2017) and that HLMS can enable high‐yield and high‐efficiency rice production.…”

“…In recent years, an increasing scarcity has occurred in the rural labor force with the acceleration of industrial restructuring and urbanization in China. The traditional seedling raising methods for mechanically transplanted rice are laborious, tedious, time consuming, and inefficient (Li et al, 2016b); thus, seedling raising method is the key factor limiting the development and large‐scale application of mechanical transplantation in Chinese rice production.…”

Durability of self-healing concrete

“…Li and Li [16] investigated engineered cementitious composite's (ECC) durability in terms of maintaining its unique tensile characteristics under combined mechanical loading and aggressive chloride conditions. ECC specimens were preloaded to 0.5, 1.0, and 1.5% tensile strain levels; immersed in chloride solution for 30, 60, and 90 days; and reloaded until failure.…”