萵苣有機肥氮當量施肥效果研究

鄧龍英 楊歡 雷周生

摘 要：為探討萵苣最佳氮施用量，進行了有機氮肥與無機氮肥組配試驗。結果表明：高有機氮與低無機氮的組合處理提高了土壤有機質含量和土壤總孔隙度，有利于提高萵苣營養品質，低有機氮與高無機氮的組合處理有利于促進萵苣植株生長、增加植株經濟性狀和產量。其中，有機氮和無機氮各5 kg/667m2的處理，兼具前兩者的有利作用，該處理與CK（不施氮肥）比較，土壤有機質含量提高1.2 g/kg，總孔隙度增加0.3個百分點，堿解氮、有效磷、速效鉀含量分別提高4.7、2.1和3 mg/kg，萵苣產量增加1 473 kg/667m2，增幅240.7%（P<0.01），純收入增加5 803.76元/667m2，增幅243.3%（P<0.01），增產增收效益極顯著，因此，建議施氮量為有機氮5 kg/667m2+無機氮5 kg/667m2。

關鍵詞：萵苣;有機肥;土壤;品質;產量;經濟效益

中圖分類號：S636.2文獻標識碼：A文章編號：1006-060X（2019）10-0043-03

Abstract： In order to explore the optimum nitrogen application amount of lettuce， the combination experiment of organic nitrogen fertilizer and inorganic nitrogen fertilizer was carried out. The results showed that the combination of high organic nitrogen and low inorganic nitrogen was beneficial to improve soil organic matter content， soil total porosity and nutritional quality of lettuce， and the combination of low organic nitrogen and high inorganic nitrogen was beneficial to promote lettuce plant growth and increase plant economic characters and yield. Among them， organic nitrogen and inorganic nitrogen treatment of 75 kg/hm2 each have the advantages of the former two. Compared with CK （no nitrogen fertilizer）， the content of soil organic matter increased by 1.2 g/kg， the total porosity increased by 0.3%， the contents of alkali-hydrolyzed nitrogen， available phosphorus and available potassium increased by 4.7， 2.1 and 3 mg/kg， respectively. The output increased by 22 095 kg/hm2， an increase of 240.7% （P < 0.01）， the net income increased by 87 056.4 yuan/hm2， an increase of 243.3% （P < 0.01）， and the benefit of increasing production and income was very significant. Therefore， it is recommended to apply 75 kg/hm2 of organic nitrogen and 75 kg/hm2 of inorganic nitrogen.

Key words： lettuce; organic fertilizer; soil; quality; yield; economic benefit

萵苣富含胡蘿卜素、硫胺素、核黃素和鈣、磷、鐵等礦質營養，既能生食、熟食，又可腌制和干制，是人們喜愛的蔬菜之一[1]。湖南各地萵苣栽培普遍，產量較高，對肥料的需求量也較大[2]。在生產實際中不合理施肥的現象普遍存在，特別是大量施用化肥，導致萵苣品質下降，肥效降低，并帶來環境污染等諸多問題。隨著國民經濟的高速發展，人們生活水平的不斷提高，市民對農產品質量的要求也越來越高，實行有機肥與無機肥相結合的施肥方法，不僅能改土壤，培肥地力，還能提高農作物產量和農產品質量，滿足人們日益增長的對農產品質量的需求。氮當量施肥是指農作物在氮素最佳施用量水平下，有機氮與無機氮的配比量[3]。為此，筆者進行有機肥氮當量施肥效果研究，以期解決氮肥施用不足或過量、偏施等問題，為有機肥料與無機肥料配方提供科學依據。……