Canopy Light Utilization and Yield of Rice under Rain-Catching and Controlled Irrigation

Abstract

In the middle and lower reaches of the Yangtze River, the rainfall is greater in summer. The technology of rain catching and controlled irrigation of rice help to save water by raising the water depth of the field after rain while the soil water content during the rest period is maintained at 70–100% of field capacity. The objectives of this study were to evaluate rice growth, canopy light utilization, and yield of rice under different rain-catching and controlled irrigation modes (T1: light drought and low storage, T2: light drought and high storage), and to find the optimal storage depth after rain for rice. Measurements included the rice plant height, tiller number, high tiller growth, leaf angle, canopy interception rate, and yield shape. The plot experiment was conducted in 2012 and 2013 using Nanjing 44 (Oryza sativa L.) as the test material. The results showed that T1 treatment improved the height of rice plants and the number of effective tillers in the late growth stage. The number of high tillers had a great influence on the total leaf dry quality; compared with conventional irrigation (CK), the number of high tillers increased by 11.36% and 7.87% in T1 and T2, respectively; the canopy interception rate of T1 above 0 cm was higher than that in T2 and CK; and the leaf area index (LAI) was closely related to the 0–40 cm of canopy light distribution. The number of grains per panicle in T1 was lower than in CK and T2; however, the number of grains in T1 was less, and the 1000 grain weight was higher. On the 63 days and 83 days after transplanting in 2012 and 78 days after transplanting in 2013, the first, second, and third leaf angles of T1 were larger. Rain-catching and controlled irrigation can increase the dry weight and shoot dry weight of rice, and light drought and low storage (T1) conditions are good for maintaining a high yield because of more tiller number, more grains per panicle and reasonable light distribution.

Response of Vertical Migration and Leaching of Nitrogen in Percolation Water of Paddy Fields under Water-Saving Irrigation and Straw Return Conditions

“…Some researchers found that appropriate degree of AWD obtained similar or increased grain yields by 9~18% compared to FI [37,[39][40][41]. However, the inappropriate control of dryness under AWD could cause reductions in rice yields [13,37,39]. The performance in rice yield in our experimental results showed good agreement with the results above.…”

“…As a result, the DP-SM has the highest irrigation water productivity, inducting the best use of water resources in a context of water scarce conditions. Some researchers found that appropriate degree of AWD obtained similar or increased grain yields by 9~18% compared to FI [37,[39][40][41]. However, the inappropriate control of dryness under AWD could cause reductions in rice yields [13,37,39].…”

“…The NH 4 + -N, NO 3 − -N and TN leaching losses in tillering stage and jointing-booting stage accounted for 74.85%~86.26% of the total amount during the whole rice growth season, which was main caused by the high value of N concentrations during this period. And the absorbing ability of plants was limited at the early growth period [37,53]. It is necessary to take effective measures to reduce N leaching losses during the tillering and jointing-booting stages, i.e., the two critical periods.…”

“…Jiangsu Province is a typical area of rice cultivation in the lower reaches of the Yangtze River. Rain-catching and controlled irrigation (RC-CI) [37], also called controlled irrigation and drainage [10,30], is a widely-used water-saving irrigation that increases water storage depth after rainfall based on controlled irrigation (CI) in Jiangsu Province. Drought planting with straw mulching (DP-SM), a water-saving irrigation regime of aerobic rice with straw return, hasn't been well tested and popularized in Jiangsu.…”

Dampak Cuaca Ekstrim terhadap Kehampaan Genotipe Padi: Pengantar Manajemen Produksi Berbasis Iklim

“…A. Malai abnormal bulir tersangkut pelepah daun bendera, B. Pelepah daun bendera patah (panah), C. Malai bergerombol, D. Bulir berisi embun air (panah) 2020). MenurutLu et al (2018) padi yang memiliki daun lebih tegak lebih tahan deraan hujan.…”