Estimation of Watermelon Nutrient Requirements Based on the QUEFTS Model

Abstract

Estimating balanced nutrient requirements for a watermelon plantation is essential to increase its fruit yield and nutrient use efficiency. This is vital for China, which produces 60% of world’s watermelons with excessive fertilizer application. Therefore, datasets between 2000 and 2019 from field experiments in major watermelon producing regions across China were collected to assess relationships between fruit yield and nutrient uptake, and to estimate nitrogen (N), phosphorus (P), and potassium (K) requirements for a target yield using a modified Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model. The results showed that the QUEFTS model predicted a linear increase in fruit yield to 60–70% of the total potential yield when balanced amounts of N, P, and K nutrients were absorbed. To produce 1000 kg of watermelon, 2.11 kg N, 0.27 kg P, and 2.69 kg K were required in shoot, and the corresponding internal efficiencies (IE) were 475, 3682, and 372 kg fruit per kg of N, P, and K, respectively. The modified QUEFTS model also simulated a balanced N, P, and K removal by fruit (accounting for 50.9%, 58.2%, and 66.4% of these nutrient accumulations in shoots, respectively). Field validation experiments further verified that the modified QUEFTS model could be used for estimating balanced nutrient requirements. Results from this study can provide practical guidance on fertilizer recommendations for improving fruit yield while preventing excessive or deficient nutrient supplies in China’s watermelon plantations.

QUEFTS Model-based Estimation of the Nutrient Requirements and Fertilizer Recommendation for Chinese Onion

“…Application of the QUEFTS model to estimate the nutrient requirements of Chinese onion. On the basis of previous studies using QUEFTS for other crops (Chuan et al, 2013;Kang et al, 2020;Liu et al, 2006;Pathak et al, 2003;Ren et al, 2016;Saïdou et al, 2003;Setiyono et al, 2010;Sun et al, 2021;Witt et al, 1999;Xie et al, 2020;Xu et al, 2013aXu et al, , 2015Xu et al, , 2019Yang et al, 2017;Zhang et al, 2018Zhang et al, , 2019, the a and d values with the corresponding 2.5% of the upper and lower IE values removed were used as the parameters of the QUEFTS to estimate the nutrient requirements for Chinese onion. The results showed that a values of N, P, and K were 308.9, 782.7, and 2004.4 kg/kg, respectively.…”

“…Both onion stem and onion leaves are edible and are regarded as economic yield. Therefore, the harvest index of Chinese onion in the study was 1, whereas other crops such as corn, peanuts, radishes, and watermelons are divided into economic and noneconomic yield, and the harvest index is 0.18 to 0.82 (Kang et al, 2020;Xie et al, 2020;Xu et al, 2015;Zhang et al, 2019). For Chinese onion with harvest index of 1, it is more convenient to use the QUEFTS model to simulate the nutrient requirements and the simulation is also more accurate, which was verified in field experiments in this study.…”

“…Simulations of nutrient requirements by QUEFTS model have been carried out for many crops, including corn (Xu et al, 2013a), wheat (Chuan et al, 2013), rice (Xu et al, 2015), rapeseed (Ren et al, 2016), sweetpotato (Kumar et al, 2016), soybean (Yang et al, 2017), peanut (Xie et al, 2020), potato (Xu et al, 2019), watermelon (Kang et al, 2020), carrot (Zhang et al, 2019), and sunflower (Duan et al, 2020). In these studies, the a value and d values were determined similarly by removing the upper and lower 2.5%, 5.0%, and 7.5% of the IE values.…”

“…The QUEFTS model has been successfully applied and evaluated in rice Sun et al, 2021;Witt et al, 1999;Xu et al, 2015), corn (Liu et al, 2006;Saïdou et al, 2003;Setiyono et al, 2010;Xu et al, 2013a), wheat (Chuan et al, 2013;Liu et al, 2006;Pathak et al, 2003), rapeseed (Ren et al, 2016), soybean (Yang et al, 2017), peanut (Xie et al, 2020), potato (Xu et al, 2019), watermelon (Kang et al, 2020), and radish (Zhang et al, 2018(Zhang et al, , 2019 in many countries including China. From the results of previous studies, this model is applicable to different crops, plant growing areas, climates, and soil types.…”

A Model for the Determination of Potato Tuber Mass by the Measurement of Carbon Dioxide Concentration

“…Another model, that can be used for different crop types, is the QUEFTS (QUantitative Evaluation of the Fertility of Tropical Soils) model [ 22 ], that can be used for the estimation of crop yield by given soil properties and the amount of applied fertilizer. This model has been used for potato [ 23 ], as well as for other crops [ 24 , 25 ]. In addition, considering other crops, it is worth noting that today there are also a number of models for the simulation of fruit tree development [ 26 ].…”