Institute of Cotton Research, Chinese Academy of Agricultural Sciences/State Key Laboratory of Cotton Biology, Anyang, Henan, The People's Republic of China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, The People's Republic of China.
PeerJ. 2022 Sep 1;10:e13894. doi: 10.7717/peerj.13894. eCollection 2022.
Plastic film mulching (PFM) affects the spatiotemporal distribution of soil moisture and temperature, which in turn affects cotton growth and the spatiotemporal distribution of canopy photosynthetically active radiation (PAR). Due to the spatial heterogeneity of soil moisture, temperature and limited monitoring methods, the issues such as relatively few sampling points and long sampling intervals in most existing studies prevent the accurate quantification of spatiotemporal changes in moisture and temperature along soil profile. To investigate the effects of PFM on spatiotemporal changes in soil moisture, temperature, and canopy PAR in cotton fields, two field trials of plastic film-mulched (M) and nonmulched (NM) cultivations were performed in 2018 and 2019. The grid method was used for the soil information continuous monitoring and multiple-time fixed-site canopy PAR monitoring during the duration of cotton growth. Two-year field trial data showed that, M cultivation increased soil moisture by approximately 13.6%-25% and increased temperature by 2-4 °C in the 0-50 cm soil layer before the first irrigation (June 20) and by 1-2 °C in the 70-110 cm soil layer, compared with NM cultivation. In addition, the temperature difference between the two treatments gradually decreased with the increase in irrigation and air temperature. The M treatment reached the peak PAR interception rate 10 days earlier than the NM treatment. In 2018 and 2019, the PAR peak value under the M treatment was 4.62% and 1.8% higher than that under the NM treatment, respectively, but the PAR interception rate was decreased rapidly in the late growth stage. Overall, PFM had an effect on soil moisture retention during the whole growth period and greatly increased the soil temperature before budding stage, thus promoted the early growth of cotton. Considering this, we suggest that the irrigation quota and frequency could be appropriately decreased in the case of plastic film mulching cultivation. For nonmulching cultivation, the irrigation quota and frequency should be increased, and it is necessary to take measures to improve the soil temperature before middle July.
塑料薄膜覆盖（PFM）影响土壤水分和温度的时空分布，进而影响棉花的生长和冠层光合有效辐射（PAR）的时空分布。由于土壤水分、温度的空间异质性以及有限的监测方法，大多数现有研究中采样点相对较少且采样间隔较长，这使得难以准确量化土壤剖面上水分和温度的时空变化。为了研究 PFM 对棉花田土壤水分、温度和冠层 PAR 时空变化的影响，2018 年和 2019 年进行了两次塑料薄膜覆盖（M）和不覆盖（NM）种植的田间试验。在棉花生长期间，使用网格方法进行土壤信息连续监测和多次固定位置冠层 PAR 监测。两年的田间试验数据表明，与 NM 处理相比，M 处理在第一次灌溉前（6 月 20 日）将 0-50cm 土层的土壤水分增加了约 13.6%-25%，并将温度提高了 2-4°C，在 70-110cm 土层将温度提高了 1-2°C。此外，随着灌溉和空气温度的升高，两种处理之间的温差逐渐减小。M 处理的 PAR 截获率峰值比 NM 处理早 10 天达到。在 2018 年和 2019 年，M 处理的 PAR 峰值分别比 NM 处理高 4.62%和 1.8%，但在生长后期 PAR 截获率迅速下降。总体而言，PFM 对整个生长期间的土壤保水有影响，并在萌芽前阶段大大提高了土壤温度，从而促进了棉花的早期生长。有鉴于此，我们建议在进行塑料薄膜覆盖种植时，可以适当减少灌溉定额和频率。对于不覆盖种植，应增加灌溉定额和频率，并采取措施提高 7 月中旬前的土壤温度。
