Effects of potassium fertilization on grain yield, taste quality, and starch characteristics of rice (Oryza sativa L.) grain.

Background: There is limited information on the effect of potassium (K) on the taste quality of rice. Field experiments with five K fertilizer application rates (0, 60, 120, 180, and 240 kg KO ha) were conducted in 2019 and 2020 using two cultivars (Xiadao No. 1 and Shenliangyou 5814) to study the effects of K fertilization on grain yield, taste quality, starch components, and protein components in grains.

Effects of optimized nitrogen fertilizer management on the yield, nitrogen uptake, and ammonia volatilization of direct-seeded rice.

Background: Direct-seeded rice has been developed rapidly because of labor savings. Changes in rice cultivation methods put forward new requirements for nitrogen (N) fertilizer management practices. Field experiments with five different fertilizer ratios of basal, tillering and panicle fertilizer, namely N1 (10:0:0), N2 (6:2:2), N3 (4:3:3), N4 (2:4:4) and N5 (0:5:5), were conducted to investigate the effects of different N fertilizer management practices on yield formation, N uptakes, and ammonia (NH ) volatilization from paddy fields in direct-seeded rice.

Rapid soil rewetting promotes limited NO emissions and suppresses NH volatilization under urea addition.

The alternation of dry and wet is an important environmental factor affecting the emission of nitrous oxide from soil. However, the consistent or opposite effects on NH and NO emissions caused by adding exogenous urea in this process have not been fully considered. Here, we controlled the initial (slow drying) and final (adding water) water-filled pore space (WFPS) at 70%, 60%, or 50% through microculture experiment to simulate a process of slow drying-fertilization and rapid wetting of the soil from rice harvest to dryland crop fertilization.

Differences in responses of ammonia volatilization and greenhouse gas emissions to straw return and paddy-upland rotations.

Paddy-upland rotation and/or straw return could improve soil structure and soil nutrient availability. Different previous crops (wheat and/or oilseed rape) and straw return methods (straw mulching and/or returning) might increase soil organic carbon (C) and total nitrogen (N) content, and further affected the ammonia (NH) volatilization, nitrous oxide (NO), and methane (CH) emissions. A comparison study was carried out in a located field experiment started from 2014 in Central China, aiming to exam seasonal and annual NH, NO, and CH emissions under the wheat-rice (WR) and oilseed rape-rice (OR) rotations.